What gear ratio do i need for my 2000 Buick LeSabre Custom

Hello,
I have a 2000 Buick LeSabre Custom, i believe it is in need of a new transmission but all sites have 4 gear ratio options. How do i determine which gear ratio I have? the 4 options they have are as follows.

Automatic Transmission FWD 2.86 ratio opt FQ3 ID PAB

Automatic Transmission FWD 2.86 ratio opt FQ3 ID PPB

Automatic Transmission FWD 3.05 ratio opt F83 ID PBB

Thank you