Consider the following statement.i. Slow sand filter is not flexible in variation in demandii. The rapid sand filter is flexible in fluctuations in demandiii. The method of cleaning of a slow sand filter involves agitation and back-washingWhich of the above statement is/are correct?

Consider the following statement.i. Slow sand filter is not flexible i

1.	Consider the following statement.i. Slow sand filter is not flexible in variation in demandii. The rapid sand filter is flexible in fluctuations in demandiii. The method of cleaning of a slow sand filter involves agitation and back-washingWhich of the above statement is/are correct?
A.	i, ii
B.	i, ii, iii
C.	ii, iii
D.	Only iii
Answer» B. i, ii, iii