Six-Month-Old Aisen Is Playing on His Back

Six-month-old Aisen is playing on his back.He accidentally grabs a toy when his hand touches a toy.He likes the noise that it makes,so he grabs the toy again and tries to shake the toy.According to Piaget,what substage of the sensorimotor stage is Aisen experiencing?

A) 1: simple reflexes
B) 2: first habits and primary circular reactions
C) 3: secondary circular reactions
D) 4: coordination of secondary schemas