Which is descriptive of a toddler's cognitive development at age 20 months?

A) Searches for an object only if he or she sees it being hidden
B) Realizes that "out of sight" is not out of reach
C) Puts objects into a container but cannot take them out
D) Understands the passage of time, such as "just a minute" and "in an hour"

At this age, the child is in the final sensorimotor stage. Children will now search for an object in several potential places, even though they saw only the original hiding place. Children have a more developed sense of objective permanence. They will search for objects even if they have not seen them hidden. When a child puts objects into a container but cannot take them out, this is indicative of tertiary circular reactions. An embryonic sense of time exists, although the children may behave appropriately to time-oriented phrases; their sense of timing is exaggerated.