As an experienced technician， you are responsible for Technical Support. Which of the followingdescriptions is correct about the characteristic of SLB one arm mode？（）

A. This out-of-band approach supports scaling
B. SLB· is not inline.
C. Mode is not as common as bridge or routed mode.
D. Return traffic requires PB·R， server default gateway pointing to SLB·， or client source NAT·