Mary finished studying for her physics exam at 10pm last night. Upon returning to the library to continue studying this morning, Mary found it...

Mary finished studying for her physics exam at 10pm last night. Upon returning to the library to continue studying this morning, Mary found it difficult to focus on the task at hand. This is illustrative of which explanation of the spacing effect? a) encoding variability b) retrograde amnesia c) attention deficit d) anterograde amnesia