(a) Marital status. A recipient shall not make pre-employment inquiry as to the marital status of an applicant for employment, including whether such applicant is “Miss” or “Mrs.”

(b) Sex. A recipient may make pre-employment inquiry as to the sex of an applicant for employment, but only if such inquiry is made equally of such applicants of both sexes and if the results of such inquiry are not used in connection with discrimination prohibited by this part.