At dinnertime, baby michael is seated in his high chair as his parents try to feed him; however, michael repeatedly drops or throws his cup, spoon, and much of his dinner onto the floor while he watch

At dinnertime, baby michael is seated in his high chair as his parents try to feed him; however, michael repeatedly drops or throws his cup, spoon, and much of his dinner onto the floor while he watches the consequences of his actions. which of piaget's substages might explain michael's behaviors?