Multifactor authentication (MFA) is the best method to ensure that the intended individual has access to sensitive data because it requires the user to provide two or more verification factors to gain access to the resources. This significantly increases security compared to single-factor methods, such as a password alone, by adding an additional layer that could involve something the user knows, possesses, or an inherent characteristic. Other methods like using a single password or an access control list are less secure on their own as they rely on one factor of authentication or could be too broad in permissions.