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 indirect form. Thus, the correct answer is Option A, no change.
Option B is incorrect - A question mark is used after a direct question.
Option C is incorrect as, a comma is not used to mark an end to a sentence.
Option D is incorrect - Dashes are used to indicate a strong pause or interruption in a sentence.