The speed of the man with respect to the bank is the difference between his swimming speed and the speed of the current. Given that he can swim at 7.0 m/s and the current is going against him at 3.7 m/s:
Speed with respect to the bank = Swimming Speed - Speed of Current
Speed with respect to the bank = 7.0 m/s - 3.7 m/s = 3.3 m/s
So, the correct answer is:
3.3 m/s