(A) In assessing the problems faced by rural migrant workers, the question of whether they are better off materially than the urban working poor is irrelevant.
(B) The question of whether the rural migrant worker is better off materially than the urban working poor is irrelevant in assessing the problems that they face.
(C) A question that is irrelevant in assessing the problems that rural migrant workers face is whether they are better off materially than the urban working poor.
(D) In an assessment of the problems faced by rural migrant workers, the question of whether they are better off materially than the urban working poor is irrelevant.
(E) The question of whether the rural migrant worker is better off materially than the urban working poor is irrelevant in an assessment of the problems that they face.
Solution:
Modifier + Pronouns + Awkwardness/wordiness
A: The opening modifier “in assessing ... workers” lacks a subject; it doesn't say who is doing “the assessing”. In fact, it suggests that “the question” (immediately following the coma) itself is performing the assessments.
B and E: “they” does not have a clear antecedent.
C: Wordy and awkward: 'a question that is irrelevant in doing X is Y' is inferior to 'the question of Y is irrelevant in doing X', because the latter is clearer and more direct.
D: Clear and direct. Best choice.
Sentence Correction - 1000 Questions with Solution: