2.
Organized in 1966 by the Fish and Wildlife Service, the Breeding Bird Survey uses annual roadside counts along established routes for monitoring of population changes of as many as, or of more than 250 bird species, including 180 songbirds.
(A) for monitoring of population changes of as many as, or of
=> we need to use to.
(B) to monitor population changes of as many, or
=> as many (as) is correct.
(C) to monitor changes in the populations of
(D) that monitors population changes of
=> It seems that the routes monitors.
(E) that monitors changes in populations of as many as, or
=> It seems that the routes monitor.
Explanation:
Why does the survey use roadside counts?
=> To do something.
We need “to + verb”
Answer is C.
NOUN+that:
উত্তরমুছুনHere, that refers to the NOUN.
Example:
I have book that is on science.
They have done the work that was hard.
--> It means that the work was hard.