For the fraudulent act or wilful wrong of a sub-agent who had been duly appointed, the sub-agent is:

In the case of a fraudulent act or wilful wrong, the sub-agent is liable to both the agent and the principal. The agent is liable because the sub-agent is acting on behalf of the agent. The principal is liable because the sub-agent is acting on behalf of the principal.

Option A is incorrect because the sub-agent is also responsible to the principal. Option B is incorrect because the sub-agent is also responsible to the agent. Option D is incorrect because the sub-agent is not responsible to the third party. The third party is only able to sue the agent or the principal, not the sub-agent.