The correct answer is that the Zero Trust Model assumes that no user, device, or network traffic should be trusted by default, even if it originates from within the network perimeter. This is the fundamental principle of the Zero Trust approach, which shifts away from the traditional "trust but verify" model to a "never trust, always verify" mindset. The other answers, while related to security concepts, do not accurately capture the essence of the Zero Trust Model. Least privilege access and multi-factor authentication are important security practices, but they are not the core defining characteristics of the Zero Trust approach.