(a) Within 15 days after service upon the respondent of the accusation, the respondent may file with the agency a notice of defense. In the notice the respondent may

(1) request a hearing;

(2) object to the accusation upon the ground that it does not state acts or omissions upon which the agency may proceed;

(3) object to the form of the accusation on the ground that it is so indefinite or uncertain that the respondent cannot identify the transaction or prepare a defense;

(4) admit the accusation in whole or in part;

(5) present new matter by way of defense.

(b) Within the time specified the respondent may file one or more notices of defense upon any or all of the grounds set out in (a) of this section but all of the notices shall be filed within that period unless the agency in its discretion authorizes the filing of a later notice.

(c) The respondent is entitled to a hearing on the merits if the respondent files a notice of defense, and the notice of defense is considered a specific denial of all parts of the accusation not expressly admitted. Failure to file the notice constitutes a waiver of the respondent's right to a hearing, but the agency in its discretion may nevertheless grant a hearing. Unless objection is taken as provided in (a) (3) of this section, all objections to the form of the accusation are waived.

(d) The notice of defense must be in writing, signed by or on behalf of the respondent, and must state the respondent's mailing address. It need not be verified or follow a particular form.