Which doctrine provides that a failure to object to a subpoena before an agency precludes a later ob

If anyone could help I'd appreciate it!!


Which doctrine provides that a failure to object to a subpoena before an agency precludes a later objection to the subpoena in District Court?
a. doctrine of estoppel
b. doctrine of double jeopardy
c. doctrine of exhaustion of administrative remedies
d.doctrine of res judicata
e. all of the above


Which of the following is not imposed upon an agency that is engaged in informal rule making
a.a final rule must be issued by the agency with a concise statement of its basis and purpose
b. interested parties are given the opportunity to participate in the rule making process
c. a trial type hearing is held
d. the agency published a notice of the rule making