The purpose of security controls testing is to evaluate the _________________ of the security controls protecting an information system. Response:

The purpose of testing security controls is to determine their effectiveness, meaning whether they are implemented correctly, operating as intended, and producing the desired outcomes to mitigate risks and protect the information system from threats and vulnerabilities. Testing verifies the controls' ability to meet security requirements.

Powerlessness is the exact opposite of the desired outcome for security controls; testing aims to confirm their strength, not their weakness.

Inefficacious means ineffective, which is precisely what security controls testing aims to prevent or identify for remediation, not evaluate as a positive trait.

Potent describes strength or power, but 'effectiveness' is the precise and standard term used in information security to describe the desired operational state and measured outcome of controls.