When Piaget and His Colleagues Asked Children of Different Ages

When Piaget and his colleagues asked children of different ages to balance a scale using several different weights, they found that _____.

A) by age 4, children tended to use logical deduction
B) by age 7, children used spatial relationships
C) by age 10, young people use trial-and-error strategies based on logic to balance the scale
D) by age 13 or 14, young people use logic to understand a reciprocal relationship