Felix Had Been Angry with His Roommate Hector for Some

Felix had been angry with his roommate Hector for some time. Hector was always playing his music so loudly that Felix couldn't concentrate, much less have a conversation on the telephone. Despite his anger, he hadn't expressed his feelings to Hector. Which of the following is true of this situation?

A) Hector and Felix are engaged in conflict because Felix's anger is sufficient to produce conflict.
B) Hector and Felix are not engaged in conflict because the source of their conflict is not interpersonal.
C) Hector and Felix are engaged in conflict because conflict can exist "under the surface" for some time.
D) Hector and Felix are not engaged in conflict because conflict must be expressed.