The Executive Board Has Requested That the CISO of an Organization

The executive board has requested that the CISO of an organization define and Key Performance Indicators (KPI) to measure the effectiveness of the security awareness program provided to call center employees. Which of the following can be used as a KPI?

A) Number of successful social engineering attempts on the call center
B) Number of callers who abandon the call before speaking with a representative
C) Number of callers who report a lack of customer service from the call center
D) Number of callers who report security issues.