One advantage of mechanical guidance is:

One advantage of mechanical guidance is that it supports safe practice for dangerous skills. Mechanical guidance involves using equipment or devices to help learners perform a skill with greater control. This is particularly beneficial in activities where there is a risk of injury, such as gymnastics or diving, as the mechanical guidance provides a protective or supportive element that can reduce the likelihood of accidents. By offering a secure environment for practicing complex or risky maneuvers, learners can build confidence and technique while minimizing the risks associated with incorrect execution.

The other options do not emphasize the primary focus of mechanical guidance, which is safety and support. While it may not be universally cost-effective, it specifically addresses the need for protection in potentially hazardous skills, making its role critical in such contexts.