A goods train 158 metres long and travelling at the speed of 32 km per hr. leaves Delhi at 6 am. Another mail train 130 metres long and travelling at the average speed of 80 km per hr. leaves Delhi at 12 noon and follows the goods train. At what time will the mail train completely cross the goods train?

• A. 4 hours
• B. 4 hours 21.6 sec.
• C. 5 hours 21.6 sec.
• D. None of these