To See Whether a Child Has Reached the Stage of Formal

Multiple Choice

To see whether a child has reached the stage of formal operations,what might a psychologist test?​

A) How the child deals with hypothetical and abstract questions
B) ​Whether the child understands that objects still exist when out of sight
C) ​Whether the child understands conservation of number and mass
D) ​How well the child can describe what an object would look like from another angle