Which Collaboration Room system requires another device to make audio or video calls?

Which Collaboration Room system requires another device to make audio or video calls?
A. Cisco Webex Room Kit Mini
B. Cisco Webex Room Kit Pro
C. Cisco Webex Room USB
D. Cisco Webex Room Kit
E. Cisco Webex Room Kit Plus

Correct Answer: C
Explanation/Reference:
Explanation: