The correct answer is can be reversed with no net change in either system or surroundings
Reversibility is a property that expresses the possibility of making the physical processes run in the opposite direction, infinitely varying the conditions that cause them.
The concept of reversibility has great importance in thermodynamics (in the foundation of its second principle), since it is the only type of processes that use the least amount of energy possible; thus, reversibly, the physical processes give their greatest performance.
In practice, it is not possible to obtain a completely reversible evolution of a process, because for this to happen, it should take place in an infinitesimal way, and, therefore, take an infinite time to complete. However, in order to obtain the highest possible efficiency, motors, machines, etc., are designed in such a way that the processes carried out on them are extremely similar to reversible processes.
