Boat&stream pblm

A man rows to a place 48 km distant and come back in 14 hours. He finds that he can row 4 km with the stream in the same time as 3 km against the stream. The rate of the stream is::

a) 1 km/hr                                                             b) 2 km/hr

c) 1.5 km/hr                                                          d) 2.5 km/hr

Watch this space for answer in a week.