what directive is needed in the HAProxy configuration to be able to log the IP of the client making the requests to the web servers?

When using HAProxy to load balance a set of web servers, what directive is needed in the HAProxy configuration to be able to log the IP of the client making the requests to the web servers?

A.
option reverseproxy

B.
option forwardfor

C.
option clientlog

D.
option exposeclient