Answer:
withdrawing
Step-by-step explanation:
Ralph Kilmann and Kenneth Thomas have developed five different types of conflict strategies including withdrawing or avoiding, collaborating, defeating, accommodation, and compromising.
Withdrawing conflict style: The term withdrawing conflict style is defined as the process that doesn't require any consideration or courage for the other person or party. An individual using withdrawing conflict styles behaves in a way that a certain incident has never happened or doesn't exist.
In the question above, Derek is using the withdrawing conflict style.