Based on Cross-Cultural Research of Piaget's Preoperational and Concrete Operational

Multiple Choice

Based on cross-cultural research of Piaget's preoperational and concrete operational stages of development, we can conclude that

A) in many cultures, children do not experience a preoperational stage.
B) in most cultures, children do not experience a concrete operational stage.
C) attainment of conservation occurs at almost the same age across all cultures studied so far.
D) age of attainment of conservation can vary by several years (2-6 years, or more) across cultures.