Two stations A and B are 230 km apart on a straight line. One train starts from A at 4 am, and travels towards B at 40 km/hr. Another train starts from B at 5 a.m, and travels towards A at a speed of 55 km/hr. At what time will they meet?

A

10 a.m.

B

7 a.m.

C

6 a.m.

D

8 a.m.