An organization wants to ensure its confidential data is isolated in a multi-tenanted environment at a well-known cloud service provider. Which of the following is the BEST way to ensure the data is adequately protected?

A. Obtain documentation of the encryption management practices.
B. Verify the provider follows a cloud service framework standard.
C. Ensure an audit of the provider is conducted to identify control gaps.
D. Review the provider's information security policies and procedures.