On flat ground, a 70-kg per-son requires about 300 W of metabolic power to walk at a steady pace of 5.0 km/h(1.4 m/s). Using the same metabolic power output, that person can bicycle over the same ground at 15 km/h. A 70-kg person walks at a steady pace of 5.0 km/h on a treadmill at a 5.0% grade. (That is, the vertical distance covered is 5.0% of the horizontal distance covered.)

If we assume the metabolic power required is equal to that required for walking on a flat surface plus the rate of doing work for the vertical climb, how much power is required?

(a) 300 W;

(b) 315 W;

(c) 350 W;

(d) 370 W.