Answer: D.) Discretionary access control
Explanation: Access control modes provides networks with a security system used for moderating, risk prevention and privacy maintainance of data and computing systems. Several access control modes exists depending on the degree of control required. In the discretionary access control approach, users are afforded the freedom and flexibility of making choices regarding permissions granted to programs. Hence, in this mode, permission are user-defined and as such sets privileges based on how the user deems fit.