A venturi meter is inserted in a pipe whose diameter is 12 in. The diameter of the meter at its throat is 6 in. and the factor C1 for the meter is .980. When a differential mercury gage is connected at the inlet and the throat of the meter, the vertical distance between the surfaces of the mercury in the two legs of the gage is 1.15 ft. The specific gravity of mercury is 13.6. The rate of discharge from the pipe is A. 5.67 cfs. B. 6.29 cfs. C. 6.05 cfs D. 6.80 cfs