what are the possible load balancing methods?

When configuring forwarding in PoxySG, what are the possible load balancing methods?
(Choose all that apply)
(a) Round Robin
(b) Fastest ICMP Reply
(c) Least Connections
(d) Least Delay

A.
a & c only

B.
b & d only

C.
a & d only

D.
b & c only