According to general rule, a direct question takes a question mark at the end whereas, a period is used at the end of an indirect sentence. The given sentence is in the form of a direct question. Thus, the correct answer is Option A, no change.
Option B is incorrect - A period is used to mark an end to a indirect sentence.
Option C is incorrect as, a comma can not used to mark an end to a sentence.
Option D is incorrect. Dashes are used to indicate a strong pause or change of thought.