The spacing of man holes along a straight portion of a sewer is 300 m, the diameter of the sewer may be__________________?
A. 0.9 cm
B. 1.2 m
C. 1.5 m
D. > 1.5 m
A. 0.9 cm
B. 1.2 m
C. 1.5 m
D. > 1.5 m