In a residential colony, sewers of diameters 100 mm, 150 mm and 225 mm were laid with a gradient 1 in 120. Which portion of the sewage system does not choke in due course of time

In a residential colony, sewers of diameters 100 mm, 150 mm and 225 mm

1.	In a residential colony, sewers of diameters 100 mm, 150 mm and 225 mm were laid with a gradient 1 in 120. Which portion of the sewage system does not choke in due course of time
A.	100 mm dia.
B.	150 mm dia.
C.	225 mm dia.
D.	all of these.
Answer» D. all of these.