​What Observation Persuaded Piaget That Young Children Lack the Concept

Multiple Choice

​What observation persuaded Piaget that young children lack the concept of object permanence?

A) They don't reach around a barrier to retrieve a toy.
B) ​They look away from a toy after seeing it for only a few seconds.
C) ​They say that a row of coins has more after they are spread out.
D) ​They say that a ball of clay weighs more after it has been squashed flat.