Conducting a penetration test is the correct answer because it involves simulating a cyber attack on the company's computer system to check for exploitable vulnerabilities. Unlike other assessment types mentioned, a penetration test is proactive and seeks to exploit weaknesses in the same way an attacker would, thus providing practical insights into the company's defensive capabilities. Vulnerability assessments, while valuable, typically identify and report potential issues rather than actively exploit them. Security audits focus on compliance with standards and policies rather than simulating attacks.