Barbara and Michael Are Presented Words to Remember for Later

Barbara and Michael are presented words to remember for later. During the testing session, they are asked to respond "old" or "new" to a series of items. Barbara's answers can be judged to be more accurate than Michael's if

A) her responses are more confident than Michael's.
B) her responses are faster than Michael's.
C) she does not have a source memory for the word.
D) she responds "know" more often than "remember."