What are the advantages that you may get in deploying ProxySG with WCCP?

What are the advantages that you may get in deploying ProxySG with WCCP? (Choose all the
apply)
(a) Scalability
(b) Redundancy
(c) Load Balancing
(d) Security

A.
All of the above

B.
a, b & c only

C.
b, c & d only

D.
a, b & d only