In chlorination, with the rise in temperature of water, death rate of bacteria____________?

A. the time taken by rainfall water to run from most distant point of water shed to the inlet of sewer
B. the time required for flow of water in sewer to the point under consideration
C. sum of (A) and (B)
D. difference of (A) and (B)

A. to increase the filtration slow sand filters capacity of
B. to increase the filtration rapid sand filters capacity of
C. for isolated buildings like pools, hotels etc swimming
D. all of the above