C is the right answer in my view.In this sentence, a comparison is made between sentences of convicted rustlers today and sentences of rustlers in the days of the early west. We must ensure the items being compared are parallel.
In A, the comparison is between sentences of convicted rustlers today and the days of the early West. This is an illogical, non-parallel comparison. The same illogical comparison in A is repeated in E as well. Eliminate A and E based on this.
A demonstrative pronoun
those rather than the object pronoun
them is needed here to point back to sentences. We can eliminate D based on this.
Between B and C, I opt for C over B because when is used to modify today in the non-underlined portion of the sentence. The use of when suggests a specific point in time that is today. Hence, to maintain parallelism between the timeframes, I opt for C because C also use when to modify the days of the early west.
Today, even when rustlers are convicted, their sentences tend to be light compared to the days of the early West when cattle rustlers were hanged from the nearest tree.
(A)
compared to the days of the early West when
(B)
compared with those in the days of the early West
in which(C)
compared with those in the days of the early West when
(D)
in comparison with
them of the early Western days when
(E)
in comparison to
the days of the early West in which