According to piaget, what is the driving force behind development from one state to the next?

It is "maturation".

Maturation alludes to the manners by which we develop all through the life. An instance of maturation is turning into a grown-up with a profession and different duties. Maturation is normally not quantifiable, and it too is for the most part impacted by hereditary qualities. 

The correct answer is maturation.

According to Piaget's theory of cognitive development, individuals progress from one stage of cognitive development to the next through the process of maturation. Maturation refers to developments and growth in a person's cognitive abilities due to biological factors as well as external factors (such as: attending school, socialization, etc.).

The correct answer is b