The correct answer is: A. 06 Hours
Loco and traffic running staff are eligible for 6 hours rest at headquarters after running duty of less than 8 hours. This is because they are required to be alert and focused while on duty, and they need time to rest and recover after a long day of work.
Option B is incorrect because it is more than the required rest time. Option C is incorrect because it is less than the required rest time. Option D is incorrect because it is not a valid option.