Final answer:
The best example of a risk mitigation approach is when workers operating dangerous machinery cannot exceed a set shift length.
Step-by-step explanation:
A risk mitigation approach is a strategy or action taken to reduce or prevent the negative impact of potential risks. Out of the given options, the best example of a risk mitigation approach is when workers operating dangerous machinery cannot exceed a set shift length. This policy ensures that employees are not overworked, reducing the likelihood of accidents and injuries caused by fatigue.