Two trains of lengths 115 and 105 metres are running on parallel lines with the respective rates of 30 and 36 km per hour. The time of crossing each other, if they run in the opposite direction is

Two trains of lengths 115 and 105 metres are running on parallel lines with the respective rates of 30 and 36 km per hour. The time of crossing each other, if they run in the opposite direction is 
(a) 10 sec. 
(h) 1 min 2 sec. 
(c) 8 sec. 
(d) 12 sec.