Which type of question can be tested through an experiment?

Correct answer: A testable question

The direct answer is A: a testable question. A question is testable when an investigation can collect observations or measurements that may support or fail to support an answer. It usually identifies measurable variables, such as whether changing the amount of sunlight changes plant height. Option A is correct because a planned experiment can change one variable, measure a response, and compare results. Option B is wrong because a personal preference, such as which colour someone likes, depends on individual taste rather than an experimental measurement of a natural relationship. Option C is wrong because an imaginary preference has no definite measurable condition to investigate. Option D is wrong because a purely emotional question asks about feelings and cannot usually be settled by measuring experimental variables alone. This does not mean feelings are unimportant; it means the question, as stated, is not answered by a normal scientific experiment. Exam cue: look for a question that can be answered with evidence, measurements, and repeatable procedures.