A GPU card can use either A or B, depending on which side of the board you approach with the power cable.
If the connector "clip" is toward the front (fan side) of the GPU and the 4 sense pins toward the back (G5090-32GTC)

and the power cable approaches from the front side of the GPU, you would need the "A"

if the power cable were to approach from the backside of the GPU, the "B" version would be needed.