Three-Month-Old Everett Sucks Vigorously on a Breast When He Is

Multiple Choice

Three-month-old Everett sucks vigorously on a breast when he is eating a meal, pressing the nipple against the roof of his mouth to maximize the milk in his mouth. He sucks firmly and rhythmically when sucking on a pacifier to fall asleep, with less pressure from his tongue. These sucking adaptations imply that Everett is in Piaget's stage _____.

A) one
B) two
C) three
D) four