To Stop Baby Rudy from Crying for a Sharp Knife

Multiple Choice

To stop baby Rudy from crying for a sharp knife on the kitchen table, his mother put it in her apron pocket. "Out of sight, out of mind," she said, and it worked. Rudy's mother has capitalized on his lack of the concept of:

A) conservation.
B) egocentrism.
C) object permanence.
D) reversibility.