Answer:
In my opinion Thato's mood can be described as unpleasant activated since he is extremely tense and nervous, and all stressed out about the possibility that the work they presented is not good and full of errors.
The closest possible answer is D) intense negative, but the question doesn't say anything about Thato being openly hostile against his coworkers (we are told he has hostile opinions about them) or being extremely depressed by their lack of commitment. He is like in between being slightly depressed (unpleasant deactivated) and openly hostile (intense negative).