Your 5-year-old brother is the baby of the family. When your mother gives birth to another child, your brother begins

Your 5-year-old brother is the baby of the family. When your mother gives birth to another child, your brother begins to soil his underwear, and your mother is

forced to put him back in diapers. Which of the following defense mechanisms is he using?
A. reaction formation
B. rationalization
C. regression
D. repression