Which rule is important for ensuring personal safety around robots?

The importance of tying up long hair when working around robots stems from safety concerns related to entanglement. Long hair can easily become caught in moving parts of a robot, which poses a significant risk of injury. Ensuring that hair is secured prevents it from being inadvertently pulled or tangled in machinery, thereby reducing the likelihood of accidents. In industrial settings and environments with robotic systems, maintaining a safe workspace is crucial, making personal safety measures like this paramount for all personnel.

The other options, while they may have their own contexts, do not directly address the critical safety issues associated with working near robotic systems. For example, keeping tools nearby might seem practical for accessibility but does not enhance personal safety around moving machines. Similarly, wearing tight-fitting clothing could be helpful in preventing snagging, but without securing hair, the risk remains. Colorful clothing does not necessarily correlate with safety and may even distract or create visibility issues depending on the environment. Thus, the focus on tying hair back is a clear and effective safety measure.