The discharge of water Q (in cubic feet per second) as it flows through an open ditch can be measured with Manning's formula:
0-1.486 p2/3 51/2
In the formula, n is the roughness factor, R is the mean hydraulic radius (in feet), and S is the slope. What is the approximate discharge of water
from a ditch with a roughness factor of 0.018, a radius of 1.6 feet, and a slope of 0.062

A. about 27.66

B. about 2.09

C. about 243.39

D. about 37.34