Because the soil there is less porous and thus less able to absorb rainfall, a flood of a given magnitude typically devastates an area many times greater in northern India than it does in central India.
(A) of a given magnitude typically devastates an area many times greater in northern India than it does in central India
Since we have “soil THERE”, we had better start with place after the “a flood”
Incorrect comparison.
(B) of a given magnitude will typically devastate many times the area if it occurs in northern India instead of central India
Since we have “soil THERE”, we had better start with place after the “a flood”
“many times… instead” is unidiomatic and thus creates incorrect comparison
(C) will typically devastate many times the area in northern India than one of comparable magnitude occurring in central India
Since we have “soil THERE”, we had better start with place after the “a flood”
“many times … than” is unidiomatic
(D) in northern India will typically devastate an area many times greater than will a flood of comparable magnitude occurring in central India
Correct choice: starts with the name of the place and makes clear about what “there talks”.
Draws a correct comparison: a flood in India and a flood in other part is compared
(E) that occurs in northern India will typically devastate many times more area than if it occurred with comparable magnitude in central India
“more area” is incorrect, we need “greater”
Hence D