The correct answer is 'Principle of Minimum Necessary Access.' This security practice is aligned with the concept of providing the least amount of access necessary for users to perform their duties, thereby limiting the potential for unauthorized access. Using 'User Discretionary Control' would mislead as it suggests a model where users control permissions to their own data, and 'Mandatory Permission Reservation' does not directly relate to a recognized principle in access control. 'Explicit Access Authorization' does not correctly describe the security practice of minimizing access rights to what is necessary.