NIBCOK00595H U4895 11/2 HXH P TRAP W/UNION JOINT PVC, White (U4895112)

Is the nut on the p-trap or the 90 angle piece?

Are the threads on the nut compatible with 1 1/2 inch male fittings on 1 1/2 inch pipe or are they a different thread at the junction?

Does anyone know the thread pitch of the union?

Is the nut on the p-trap ot on the 90?