Which configuration is correct for a DHCP Relay Proxy?

A.
setdhcp relay 1.1.1.1
setdhcp relay 2.2.2.2
setdhcp relay

B.
setdhcp relay proxy
setdhcp relay 1.1.1.1
setdhcp relay 2.2.2.2

C.
setdhcp relay 1.1.1.1 proxy
setdhcp relay 2.2.2.2

D.
setdhcp relay 1.1.1.1
setdhcp relay 2.2.2.2 proxy