akshaygundeti
egmat could you please explain the difference between options D & E
I am no expert, but I will try to explain my understanding. Pl let me know whether this works for you.
Assuming that you were able to eliminate A,B, and C, let's dissect D and E with original sentence.
D. The appearance of a contagious disease
usually occasioned a concerted effort to clean streets and remove garbage
an effort which by the early 19th century gave rise to sanitary reform to prevent infectious disease
and ranged from cleaning streets and removing garbage, to ensuring clean water supplies and effective sewage removal
The reason D is wrong is that D could mean wrong parallelism. i.e, the appearance of a contagious disease usually occasioned [..] and ranged from [...]. It could mean that the appearance of a diseased ranged from X to Y. But actually, it is the effort that ranged from X to Y. X and Y refer to another parallel list. (cleaning streets bla bla bla).
You could assume
ranged is parallel to
gave. In that case the meaning is clear. But the sentence can be read in two different ways. We will look at E now.
E. an effort
which
by the early 19th century gave rise to sanitary reform to prevent infectious disease
and which ranged from cleaning streets and removing garbage, to ensuring clean water supplies and effective sewage removal.
Now the parallelism is clear. We are looking at a noun modifier. This modifier refers to the concerted effort.
Now the sentence reads, an effort which gave X and which ranged from Y to Z.
E clears ambiguity that D has. So, E is the answer choice.