Which one of the following statements about the All India Services is correct?

• A. The All India Services may be created by an Act of the Parliament.
• B. The endorsement of the Rajya Sabha is not essential for the creation of the All India Services.
• C. The rules of recruitment to the All India Services are determined by the UPSC..
• D. The conditions of service to the All India Services may be altered by the UPSC.