When optimizing a standalone point-to-multipoint bridge installation with eight non-root bridges. Which of the following rts threshold and cwmin settings would be correct for the non-root bridges？（）

• A、rts threshold=4000，cwmin=3
• B、rts threshold=1，cwmin=4
• C、rts threshold=4000，cwmin=5
• D、rts threshold=1，cwmin=5