Infants under extended hospital care in nonstimulating environments often fail to gain weight and tend to develop respiratory conditions and fever. This condition is known as

An embryo cannot develop without at least one X chromosome

Indicate whether this statement is true or false.

Sylvia loves to play with her toy telephone. When she holds the receiver to her face and calls "Hi!" she is engaging in which type of play?

A) Sensorimotor B) First pretend play C) Substitute pretend play D) Rule-governed play