Concept:An agency contract is the legal agreement that creates the principal-agent relationship.
Explanation:The contract of agency is formed between two main parties.
One party, called the principal, gives authority to the other party, called the agent.
The agent is then empowered to act on behalf of the principal.
Although the agent may later deal with a third party, that third party is not a party to the agency contract itself.
Therefore, the essential parties in an agency contract are the principal and the agent.
Answer:B. a principal and an agent