Explanation

Power is defined as the rate of doing work, P = Fv, where F is the force applied in the direction of motion and v is the velocity. Here the snowboard moves at 5 m/s while the tow rope supplies 3000 watts of power, so the force is F = P/v = 3000/5 = 600 N. The units confirm it: one watt is one joule per second and a joule is a newton-metre, so watts divided by m/s gives newtons directly. Options A (50 N) and B (100 N) would correspond to far too little power for a 5 m/s climb, while D (1500 N) wrongly multiplies power by velocity instead of dividing. Hence the applied force is 600 N, option C.