(a) The surviving spouse of any member who dies by reason of injury, illness or disease resulting from an occupational risk or hazard inherent in or peculiar to the service required of members, while the member was or is engaged in the performance of his or her duties as an emergency medical services officer, or the survivor spouse of a member who dies from any cause while receiving benefits pursuant to §16-5V-19 of this code, is entitled to receive and shall be paid from the fund benefits as follows: To the surviving spouse annually, in equal monthly installments during his or her lifetime an amount equal to the greater of:

1. (1) Two thirds of the annual compensation received by the deceased member during the last 12 full months of contributory service; or (2) if the member dies after meeting early or normal retirement age requirements, the monthly amount which the spouse would have received had the member retired the day before his or her death, elected a one hundred percent joint and survivor annuity with the spouse as the joint annuitant, and then died.