In a Series of Studies,when Older Adults Were Assigned to Theater-Arts

In a series of studies,when older adults were assigned to theater-arts training,singing lessons,or no-intervention control groups,__________.

A) theater-training participants showed greater gains on tests of working-memory capacity
B) there were no discernable differences in scores on tests of instrumental activities of daily living
C) singing-lesson participants showed greater gains on tests of word and prose recall and verbal fluency
D) theater-training participants showed smaller gains than singing-lesson participants in problem solving