In which instance is it permissible to attach a device to a bike or sled?

In the context of regulations regarding the attachment of devices to bikes or sleds, the appropriate understanding is that it is generally prohibited due to safety concerns and potential hazards. The attachment of devices, such as sleds, can drastically affect steering, braking, and overall control, especially in various conditions such as going downhill or during competitive events.

Allowing attachments only during competitions might suggest that safety standards are relaxed, which is not the case; safety remains a priority regardless of the scenario. Additionally, suggesting that attachments are only permissible if deemed necessary for safety could lead to subjective interpretations and varies from person to person. Therefore, the strict guideline remains that attaching devices is not permissible in these instances, resulting in the conclusion that it is appropriate to say that none of the options provided align with regulations regarding safe practices for bikes or sleds.