The correct answer is C. 03.
The Railway Board’s General Instructions for Loco Running (GIR) state that “Not more than three officials shall travel in the locomotive unless authorised by the operating official.” This is to ensure that the locomotive is not overloaded and that there is enough space for the crew to operate the train safely.
Option A is incorrect because it states that no more than two officials can travel in the locomotive. This is not in accordance with the GIR.
Option B is incorrect because it states that no more than four officials can travel in the locomotive. This is also not in accordance with the GIR.
Option D is incorrect because it states that no more than six officials can travel in the locomotive. This is clearly too many people to be safely accommodated in a locomotive.