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·