How many users are supported on the Cisco Unified Communications models 540 and 560 platforms？（）
- A 16 users on the UC540 and 64 users on the UC560
- B 32 users on the UC540 and 64 users on the UC560
- C 32 users on the UC540 and 104 users on the UC560
- D 16 users on the UC540 and 104 users on the UC560