According to Piaget, Children Enter into the __________ Stage About

According to Piaget, children enter into the __________ stage about age 11 wherein children begin to understand __________.

A) sensorimotor; objects continue to exist even when they are not in sight
B) preoperational; that matter can change shape but does not necessarily change volume
C) concrete operational; the relationships between sets of objects
D) formal operations; how to think abstractly, logically, and systematically