14 C.F.R. § 323.11 – Answers to objections.

(a) Any person may file an answer to an objection filed under this part.
(b) An answer must be filed not later than 7 business days after the filing of the objection to which it responds. Late-filed answers may be allowed, and extensions of filing time granted, by the Department for the same reasons as for objections.
(c) An answer may contain the same type of facts and discussion permitted for objections under this part, and must contain:
1. (1) Proof of service on the objector, on all persons on whom the objection was required to be served, and on any other person designated by the Department. The proof of service shall include the names and addresses of all persons served.
2. (2) Identification of the answering party, including address and telephone number.
  (Approved by the Office of Management and Budget under control number 3024-0030)