After which of the following situations would it usually not be necessary to notify third parties of the termination of an agency's existence?
　　a. The destruction of the subject matter of the agency.
　　b. A termination by the principal.
　　c. The achieving of the agency's purpose.
　　d. A termination by mutual agreement.
　　Answer:A
　　Choice "a" is correct. Notification to third parties is not required when actual authority of an agency relationship terminates as an operation of law. These include death of either the principal or the agent, incapacity of the principal, discharge in bankruptcy of the principal, failure to acquire a necessary license, destruction of the subject matter, or subsequent illegality.
　　Choices "c", "d", and "b" are incorrect, per the above rule.