✅ "Atlantic Ocean" is the specific name of a unique geographical body of water, making it a proper noun.

❌ "Doctor" in this context is a common noun referring to a profession, even if sometimes capitalized as a title when followed by a name.

❌ "French" is a proper adjective, derived from the proper noun "France," used here to describe the language ("French language").

❌ "President" is a common noun referring to a general office or position, not a specific individual or unique title.

✅ While "Quest" is capitalized in the sentence, it functions as a common noun referring to a journey or search, not a unique, specific name for the expedition itself. Its capitalization here is likely for emphasis or stylistic reasons, which does not change its grammatical classification to a proper noun; it remains a generic noun describing the action.

❌ "King Arthur" is a proper noun because it refers to a specific, legendary monarch.

❌ "Knights of the Round Table" is a proper noun because it refers to a specific, named group or order of knights.

❌ "Holy Grail" is a proper noun because it refers to a specific, legendary artifact.

✅ 'Golden Gate Bridge' is a single, indivisible proper noun representing a specific landmark. While 'Golden' and 'Gate' are common words (an adjective and a common noun, respectively), when combined with 'Bridge' in this specific order, they form the unique name of the structure. Removing any part or changing the order fundamentally changes or destroys the proper noun's identity as that specific bridge; 'Golden' or 'Gate' alone are not proper nouns in this context.

❌ 'Doctor Who' is a proper noun representing a specific character/series. Here, 'Doctor' acts as a proper noun title, and 'Who' functions as a unique proper noun identifier within the name, making them distinct proper noun components rather than common words fully integrated into a new proper noun name.

❌ 'President Obama' consists of two distinct proper nouns: 'President' (a title used as a proper noun) and 'Obama' (a proper noun surname). Each component maintains its proper noun status independently and can exist as proper nouns outside the specific combination.

❌ 'Atlantic Ocean' is a multi-word proper noun, but 'Atlantic' functions as a proper noun (describing a specific region/concept) and 'Ocean' is a common noun that describes the type of geographical feature. Thus, 'Atlantic' retains its proper noun quality even when considered apart from the full phrase, unlike 'Golden' or 'Gate' in the correct option.

✅ "Grandmother" is capitalized only when used as a direct name or title (e.g., "I asked Grandmother for help"). When preceded by a possessive pronoun like "my" (as in "My Grandmother"), it functions as a common noun and should typically not be capitalized. The rule is: (Possessive + Family Title) = Common Noun (e.g., my mother, his aunt), while (Family Title as name) = Proper Noun (e.g., Mother, Aunt Susan).

❌ "Catholic" refers to a specific religious denomination, which is a proper noun and correctly capitalized.

❌ "World War II" is the specific name of a major historical event, making it a proper noun and therefore correctly capitalized.

❌ Option D is incorrect because "Grandmother" is capitalized incorrectly in this specific context according to standard English grammar rules.

✅ "Monday" is a proper noun because it is the specific name of a day of the week, and all days of the week are inherently proper nouns, always capitalized.

❌ "River" is a common noun, referring to a general type of flowing water body. It only becomes part of a proper noun when combined with a specific name, such as "Amazon River."

❌ "Season" is a common noun, referring to a general division of the year (e.g., spring, summer). Even the names of seasons themselves (like 'spring' or 'summer') are typically considered common nouns unless personified or part of a specific proper name like "Spring Break."

❌ "Language" is a common noun, referring to a general system of communication. Specific names of languages, such as "English" or "French," are proper nouns, but "Language" itself is not.