Head width of 52 kg rail section is A. 61.9 mm B. 66.7 mm C. 67 mm D. 72.33 mm

The correct answer is A. 61.9 mm.

The head width of a 52 kg rail section is 61.9 mm. This is the distance between the two flanges of the rail, measured at the top of the rail. The flanges are the raised portions of the rail that help to keep the train on the track.

The other options are incorrect. Option B is the head width of a 43 kg rail section. Option C is the head width of a 60 kg rail section. Option D is the head width of a 70 kg rail section.

I hope this helps!