The correct answer is A. deriding.
Deriding is the act of making fun of someone or something in a cruel or mocking way. It is often done in a way that is intended to humiliate or belittle the person or thing being derided.
Pushing is the act of applying force to something in order to move it. It can be done in a gentle or forceful way, depending on the situation.
Praising is the act of expressing admiration or approval for someone or something. It is often done in a way that is intended to make the person or thing being praised feel good about themselves.
Supporting is the act of providing help or encouragement to someone or something. It can be done in a variety of ways, depending on the situation.
In the context of the question, James had the habit of exhausting his colleagues. This suggests that he was likely to make fun of them, belittle them, or otherwise put them down. This would be consistent with the definition of deriding.
The other options are not as consistent with the context of the question. Pushing could be seen as a way of exhausting someone, but it is not necessarily done in a cruel or mocking way. Praising and supporting are both positive actions that are not likely to exhaust someone.