(1) For the purpose of providing the annuities for the beneficiaries, the trustees shall—

(a) enter into a scheme of insurance with the Life Insurance Corporation established under the Life Insurance Corporation Act, 1956 (31 of 1956) or any other insurer as defined in section 2(58) of the Act; or

(b) accumulate the contributions in respect of each beneficiary and purchase an annuity from the said Life Insurance Corporation of India or any other insurer at the time of the retirement or death of each employee, or on his becoming incapacitated prior to retirement