Concept:An agent is a person appointed to act on behalf of another, called the principal, to create legal relations with third parties.Explanation:The agent represents the principal in business dealings.The agent brings the principal into a contractual relationship with a third party.This relationship is binding on the principal, provided the agent acts within their authority.A consignee or consignor deals with goods on behalf of another but is not specifically appointed to form contracts for the principal.Answer:D. an agent