which field is populated by a DHCP relay agent with its own IP address before the DHCPDISCOVER message is forwarded to the DHCP server?

Refer to the exhibit.

According to this DHCP packet header, which field is populated by a DHCP relay agent
with its own IP address before the DHCPDISCOVER message is forwarded to the DHCP
server?

A.
ciaddr

B.
yiaddr

C.
siaddr

D.
giaddr