Nine-year-old desi is in the stage of cognitive development whereas her 15-year-old brother is likely in the stage. a. concrete operations; formal operationsb. preoperational; concrete operationsc. sensorimotor; preoperationald. formal operations; sensorimotor

A. concrete operations; formal operations

Explanation:

The concrete operations stage is when children are able to start thinking in a more logical and organized form about specific events. Also, they began to think about the feelings of other people. This stage is when kids are between 7 and 11 years old.

The formal operations stage is when children start to analyze hypothetical problems and think in an abstract form. This stage is when kids are 12 and up.

According to this, Nine year old Desi is in the concrete operations stage and her 15-year-old brother is likely in the formal operations stage.

answer; /// i believe the correct answer is (when one group has an extremely high score at pretest;