If memory development is a problem in object permanence, which of the following examples would exemplify this?

a. If an object is moved from one location to another, the infant cannot remember where it went.
b. An infant reacts strangely when she sees an object pop up in a different-than-expected location.
c. An infant watches a toy drop off the edge of their chair.
d. An infant looks under a blanket for his hidden toy.

A. If a toy is moved from one location to another, some theorists feel that infants do not have the ability to remember seeing the object and seeing it moved.