The correct option is C 5 hour
Distance covered in 1 hour = 60 km
Distance coverd in 2 hour = 60 + 60 = 120 km
Distance covered in 3 hour = 60 + 60 + 60 = 180 km
Similarly, Distance coverd in 5 hour = 60 + 60 + 60+ 60 +60 +60 = 300 km
S0, the train will take 5 hours to cover the distance of 300 km