A.NPIV and vSCSI both require multipathing in VIO Server only.
B.NPIV requires multipathing software on client LPARs, vSCSI requires multipathing software on VIO Server.
C.NPIV requires multipathing software on VIO Server, vSCSI requires multipathing software on client LPARs.
D.NPIV requires multipathing and MPIO software on VIO Server LPARs, vSCSI requires multipathing software on VIO Server and MPIO on client LPARs.