How does a cloud access security broker function?

A、it acts as a security information and event management solution and receives syslog from other cloud solution
B、It integrates with other could solutions via APIls and monitors and creates incidents based on evets from the cloud solution
C、It is an authentication broker to enable single sign-on and mutil-factor authentication tor a cloud solution
D、it scans other cloud solutions being Used whin the network and identifies vulnerabilities.