✅ Option A uses the Second Conditional structure: "If + past simple, would + base form." This structure is correctly used to describe a hypothetical or unreal situation in the present or future, and its probable result.

❌ Option B uses the First Conditional, which describes a real and likely future situation, not a hypothetical present one.

❌ Option C uses the Third Conditional, which refers to an unreal situation in the past and its past result, not a hypothetical present situation.

❌ Option D is grammatically incorrect. "Would" is not typically used in the 'if' clause of standard conditional sentences, and the main clause structure is also incorrect for any standard conditional type.