Implementing mock phishing exercises is the most effective way to validate organizational awareness of cybersecurity risk, because it helps to measure and test the knowledge and behavior of the employees regarding the detection and prevention of phishing attacks, which are one of the most common and dangerous forms of cybersecurity risk. A phishing attack is a fraudulent attempt to obtain sensitive or confidential information, such as usernames, passwords, or credit card details, by impersonating a legitimate or trusted entity, such as a bank, a government agency, or a colleague, through email, phone, or other communication channels. A mock phishing exercise is a simulated phishing attack that is conducted by the organization or a thirdparty to assess the level of awareness and readiness of the employees to recognize and respond to phishing attacks, and to provide feedback and training to improve their skills andknowledge. Implementing mock phishing exercises is the most effective way, as it helps to validate the actual and practical awareness of cybersecurity risk, and to identify and address the gaps or weaknesses in the employees' awareness and behavior. Conducting security awareness training, updating the information security policy, and requiring two- factor authentication are all useful ways to enhance organizational awareness of cybersecurity risk, but they are not the most effective way, as they do not directly validate the awareness and behavior of the employees regarding phishing attacks. References = Risk and Information Systems Control Study Manual, Chapter 4, Section 4.3.2, page 158