Explanation:
Mandatory access controls restrict access to files based on the security classification of the file. This prevents users from sharing files with unauthorized users. Role-based access controls grant access according to the role assigned to a user; they do not prohibit file sharing. Discretionary and lattice-based access controls are not as effective as mandatory access controls in preventing file sharing. A walled garden is an environment that controls a user’s access to web content and services. In effect, the walled garden directs the user’s navigation within particular areas, and does not necessarily prevent sharing of other material.