Eliska Is Nine Months Old

Multiple Choice

Eliska is nine months old.One of her favourite games is peek-a-boo,and recently she has begun to pry at her mother's fingers when mother covers her face.Eliska has developed _______________,the understanding that mother is still behind her hands even when Eliska can't see her.

A) sensory operations
B) concrete operations
C) conservation
D) object permanence