The correct answer is: B. Day and Night.
Track maintenance machines are permitted to work during the day and night, as long as they are properly equipped and operated in a safe manner. Some of the safety precautions that must be taken when operating a track maintenance machine include:
- Wearing proper safety gear, such as hard hats, safety glasses, and hearing protection.
- Inspecting the machine for any defects before operating it.
- Operating the machine in a safe manner, following all applicable safety regulations.
- Being aware of the surroundings and taking precautions to avoid accidents.
Track maintenance machines are essential for keeping railway tracks in good condition. By working during the day and night, track maintenance crews can ensure that the tracks are always safe and ready for use.
Option A is incorrect because track maintenance machines are not permitted to work during the day only. Option C is incorrect because track maintenance machines are not permitted to work during the day clear weather only. Option D is incorrect because track maintenance machines are permitted to work during the day and night.