Step 1: Understanding the Concept:
The question asks about the various modes by which a contract of agency can be terminated or brought to an end. The Indian Contract Act, 1872, in Sections 201 to 210, outlines these different modes.
Step 2: Detailed Explanation:
Termination of agency can occur in two broad ways: by the act of the parties or by operation of law. Let's analyze the options based on Section 201 of the Act:
\begin{itemize}
\item (A) Agreement between parties: An agency, being created by an agreement, can also be terminated by a mutual agreement between the principal and the agent at any time. This is a valid mode of termination by the act of parties.
\item (B) By renunciation by the agent: The agent can terminate the agency by giving reasonable notice and renouncing the business of the agency. This is also a valid mode by the act of a party. (Similarly, the principal can revoke the agent's authority).
\item (C) By completion of business of agency: This is a mode of termination by operation of law. When the specific task for which the agency was created is completed, the agency relationship automatically comes to an end as its purpose has been fulfilled.
\end{itemize}
Since all the options listed—(A) mutual agreement, (B) renunciation by the agent, and (C) completion of the business—are valid and recognized methods for terminating an agency, the correct answer is all of the above.
Step 3: Final Answer:
The correct answer is All the above.