9. Solar radiation supplies approximately 1 kW/m² at the earth's surface. A 3 m x 2 m solar collector is used to heat water. If the required temperature rise is 40°C, what is the necessary flow rate of the water in kg/s? Assume the water absorbs 80% of the radiant energy. (A) 28.6 g/s, (B) 35.75 g/s, (C) 63.66 g/s, (D) 79.58 g/s.