Which Statement Regarding the Effectiveness of Studying the Same Material

Which statement regarding the effectiveness of studying the same material twice versus studying once and quizzing yourself once to enhance recall on a memory test is true?

A) Studying twice yields higher recall only if the memory test is at least two days from the study period.
B) Studying and then quizzing will yield higher recall no matter when the test is given.
C) Studying and then quizzing will be more effective as the time needed to retain the information increases.
D) Studying twice or studying and then quizzing are equally effective.