1. (a) made in writing on a blank provided by the Comptroller for such purpose; and
2. (b) ineffective until it is filed in the Comptroller's office; and

3. (c) revocable to the extent that:

   1. (1) a new beneficiary under option three or option four may be designated at any time during the member's life;
   2. (2) a new beneficiary under any other option may be designated at any time within the period provided for the making of an election pursuant to this section.

A member, or person authorized by section 514 of the Retirement and Social Security Law to make an election on a member's behalf, may designate a beneficiary under any of the options herein provided. Each such designation shall be: