(a) Time of filing. Within 30 days after the filing of the petition, the Administrator shall file an answer thereto: Provided, That if a motion to dismiss the petition, in whole or in part, is made pursuant to § 900.52(c), the answer shall be filed within 15 days after the service of an order of the judge denying the motion or granting the motion with respect to only a portion of the petition. The answer shall be filed with the hearing clerk who shall cause a copy thereof to be served promptly upon the petitioner.

(b) Contents. The answer shall specify which of the material allegations of fact or of law in the petition are controverted and which are not controverted. The answer also may contain affirmative allegations of fact constituting separate defenses and statements of objections to the sufficiency of the whole or any part of the petition.