The Difference Between the Schemes of Substage 2 Infants and Substage

The difference between the schemes of substage 2 infants and substage 3 infants is that

A) substage 2 infants use schemes for the pleasure of using them, whereas substage 3 infants use schemes to explore the environment.
B) substage 2 infants are limited to reflexive activity, whereas substage 3 infants develop skills and action patterns to interpret the world.
C) substage 2 infants can reproduce activities they happen upon by chance, whereas substage 3 infants can employ means-ends analysis to produce a desired effect.
D) the schemes of substage 2 infants are limited to single sensory modalities whereas the schemes of substage 3 infants involve the coordination of input from more than one modality.