Three-month-old Alex is lying in his crib. As he moves, he accidentally gets his foot in his mouth. He laughs and puts his foot in his mouth again. This activity is called

A) assimilation.
B) sensorimotor play.
C) fine motor skills.
D) symbolic play.

B) sensorimotor play. Sensorimotor play evolves mostly around the practice of sensory activity and the development of new motor actions.