In circular sewers if depth of flow is 0.2 times the full depth, the nominal gradient,

In circular sewers if depth of flow is 0.2 times the full depth, the

1.	In circular sewers if depth of flow is 0.2 times the full depth, the nominal gradient,
A.	Is only provided
B.	Is doubled
C.	Is trebled
D.	Is not enough
Answer» C. Is trebled