In a Series of Studies, Wynn Used Baillargeon's Possible Event-Impossible

In a series of studies, Wynn used Baillargeon's possible event-impossible event procedure to study 5-month-old infants' understanding simple addition and subtraction. Infants' reactions:

A) did not differ between possible and impossible event situations.
B) reflected surprise when possible events were depicted, but not when impossible events were depicted.
C) suggested that the infants have rudimentary arithmetic ability, but other interpretations of the findings are possible.
D) were difficult to interpret, because object permanence was a necessary skill that the 5-month-olds did not have yet.