Which of the following statements is most correct about the structure and powers of federal administrative agencies?
a. administrative agencies are located in the executive branch and can perform congressionally delegated executive, legislative, and adjudicatory functions
b. agencies are located in the executive branch and can perform legislative powers but not adjudicatory powers which are limited to the judicial branch of government
c. agencies are located in the executive branch and can only perform executive enforcement functions
d. agencies are located in the executive branch and can perform adjudicatory functions but not legislative functions which are limited to the legislative branch of government