1. (a) That's right. To secure payment of moneys owed to the agent by the principal, an agent has a lien over any property of the principal that is lawfully in the agent's possession. A lien gives the agent a right to retain possession of the principal's property until the principal has made any due payments.

In this case, as long as B has not already returned the truck to A, he is entitled to continue to possess it until A pays him what is owed.