Answer:
the presence of cell structures in the cell
Explanation:
<em>If you do not know the reasoning behind this, you may want to read the explanation assignment the teacher adds, or do more research, look at notes, or pay attention during class :)</em>
The correct answer is b.
The child is reaching for a toy which is not visible to him (hidden under a cloth), therefore, the child has a mental representation of the object in his/her mind. This action means that the child acknowledges that the objects continue to exist even when he/she can not hear or see them. This thought process is called object permanence and it is an ability acquired between the 4th and 7th month of a child's development.
