(a) Requirements; all candidates. Except as provided in § 21.54, and as otherwise provided in this section, every candidate for examination for appointment in the grade of junior assistant:

(1) Shall be a citizen of the United States;

(2) Shall be at least 18 years of age; and

(3) Shall have been granted an academic or professional degree from an approved school, college, or postgraduate school, and, unless the required professional training has been otherwise obtained from an approved school, college, or postgraduate school, shall have majored in the profession in which the examination is being held.

(b) [Reserved]

(c) Special requirement; therapists. Every candidate for examination for appointment as a therapist shall have received a certificate from an approved school of physical therapy or an approved school of occupational therapy.