An IT professional runs tests to make a networked printer "fail," and then assess the recovery time.

What is the IT professional testing?

fault tolerance

spoolers

shared resources

routing protocols

The IT professional is testing fault tolerance.

Think of fault tolerance as a contingency plan, a property that ensures the machine will continue to run if a part or program fails. For example, my iPhone is fault-tolerant. It can run even if the home button is damaged, considering it's intentionally made to be a non-crucial part.