Jordan Is Five Years Old

Jordan is five years old. His mother says to him "If you have two apples and I give you two more apples, how many apples will you have?" Jordan correctly says "four apples." Then, his mother says "if you have four apples, and you give two to me, how many apples will you have left?" Jordan replies "four." What is Jordan's area of difficulty?

A) Jordan has difficulty with the concept of reversibility.
B) Jordan has difficulty with the concept of conservation.
C) Jordan has difficulty because he is egocentric.
D) Jordan has difficulty with hypothetical reasoning.