What is the definition of availability accord to CVSSv3 framework?

What is the definition of availability accord to CVSSv3 framework?
A. This metric measures the impact to the confidentiality of the information resources that are managed by a software component due to a successfully exploited vulnerability.
B. This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information.
C. This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability.