(1) Class A members shall be those members who are covered by the provisions of Title II of the Federal Social Security Act and who contribute hereunder for benefits supplementary to the Social Security benefits. It shall consist of:

(i) all employees who were members prior to the date coverage under the Social Security Act is extended to such class A members, and who prior to September 1, 1959 on a form approved by the board waive their rights to benefits accrued to them under this chapter as it existed prior to March 11, 1959, elect to be covered by said Social Security Act and the supplementary benefits provided by this chapter, as amended, and agree to the deduction of their accrued taxes, if any, under the Federal Insurance Contributions Act for the period from January 1, 1956, from the accumulated contributions held in their accounts in the employees' fund, and who make payment, prior to September 30, 1959, of any lump sum amount required under the provisions of § 8-3432 hereof; and

(ii) all employees who were eligible to elect to become class A members and to be covered under the Social Security Act as provided in (i) above but did not so elect, and who, if a future amendment of the Social Security Act should so permit, elect to become class A members and to be covered under the Social Security Act in accordance with the terms of an agreement, if any, between the state of Tennessee and the social security administration; and

(iii) all employees who enter the membership on or after the date coverage under the Social Security Act is extended to such class A members except employees in positions to which such coverage is not extended.

(2) Class B members shall consist of those employees who were members prior to the date coverage under the Social Security Act is extended to class A members and who have not elected to become class A members, and all employees in positions to which such coverage is not extended except commissioned members of the department of safety.

(3) Class C members shall consist of all commissioned members of the department of safety and shall also include any person having at least twenty-two (22) years of service as a class C member of the Tennessee state retirement system on January 1, 1965 and who becomes warden of a Tennessee state prison prior to July 1, 1965.