Piaget believed the major achievement of the final substage in the sensorimotor stage is

Piaget believed the major achievement of the sensorimotor stage is object permanence. Object permanence is the understanding that people/things continue to exist even though they cannot be seen or experienced. Brings new meaning to the game of peek-a-boo!

The answer to this question is a companionate love. A companionate love is a type of non passionate love where there is a deep and big commitment from one another. This type of love is stronger than friendship and is intimate and an allegiance to one another is always there.