Which of the following describes a personal fall arrest system?

A personal fall arrest system is specifically designed to prevent a fall from height by stopping the fall before a worker can reach the ground or a lower level. This type of system typically includes components such as a harness, lanyard, lifeline, and an anchor point. Its primary function is to ensure the safety of workers who are performing tasks on elevated surfaces by securely arresting their descent in case they lose their balance or slip.

The other options describe different aspects related to worker safety or ergonomics but do not specifically capture the intended purpose of a fall arrest system. For instance, systems that hold a person while they work may refer to scaffolding or other supports, while resting systems or tool support systems focus on comfort and access rather than fall prevention. Thus, the correct answer is C, as it clearly identifies the critical role of a personal fall arrest system in protecting individuals working at heights.