1. (a) the service rendered with the previous employer was originally credited under the section 384-d plan; or
2. (b) the previous employer adopted section 384-d coverage prior to the member's retirement or termination of membership; or
3. (c) the current employer did not adopt section 384-d coverage until after the member commenced employment with such employer.

A member who retires, dies or separates from service on or after April 1, 1994, while enrolled in the retirement plan provided by section 384-d of the Retirement and Social Security Law, shall receive credit under such plan for service rendered with a previous police or fire department employer under the following circumstances: