Where a person:
(a) became entitled to an invalidity pension under section 66 after attaining his or her minimum retiring age;
(b) did not make an election under section 69 or 72;
(c) would, if he or she had resigned or had retired otherwise than on the ground of invalidity, have been entitled to a pension under section 55 or 59; and
(d) has not attained the age of 65 years;
the person may make, by notice in writing to CSC, an election to renounce the invalidity pension and, where the person does so, the person is not entitled to the invalidity pension on and after a day determined by CSC (not being a day earlier than the day on which the election was made).