Explanation: Discretionary access control is the control system that is imposed over the information system. The information systems contains different objects and subjects that gets the permission to do the operations.
The operation which the components can do are sharing the data to other object or subjects, privilege providence, change in the rules for the access, security entities getting changed etc.
Fist one correct. second wrong because not all heat is used for work, some of it lost to other. third wrong because fuel burn inside is called combustion engine <span />
