(c) (1) The provisions of this section concerning age shall not apply to: (A) The termination of employment of any person with a contract of unlimited tenure at an independent institution of higher education who is mandatorily retired, on or before July 1, 1993, after having attained the age of seventy; (B) the termination of employment of any person who has attained the age of sixty-five and who, for the two years immediately preceding such termination, is employed in a bona fide executive or a high policy-making position, if such person is entitled to an immediate nonforfeitable annual retirement benefit under a pension, profit-sharing, savings or deferred compensation plan, or any combination of such plans, from such person's employer, which equals, in aggregate, at least forty-four thousand dollars; (C) the termination of employment of persons in occupations, including police work and fire-fighting, in which age is a bona fide occupational qualification; (D) the operation of any bona fide apprenticeship system or plan; or (E) the observance of the terms of a bona fide seniority system or any bona fide employee benefit plan for retirement, pensions or insurance which is not adopted for the purpose of evading said provisions, except that no such plan may excuse the failure to hire any individual and no such system or plan may require or permit the termination of employment on the basis of age. No such plan which covers less than twenty employees may reduce the group hospital, surgical or medical insurance coverage provided under the plan to any employee who has reached the age of sixty-five and is eligible for Medicare benefits or any employee's spouse who has reached age sixty-five and is eligible for Medicare benefits except to the extent such coverage is provided