answer choice here

@Lucas, The author discusses two approaches to study of socioeconomic achievement and argues that only analysis of supply-side and demand-side factors together will suffice (lines 23-26). In other words, he advocates for a synthesis of the two approaches as (A) correctly states. He is not evaluating the soundness of the theories as (C) suggests, rather he agrees that both perspectives/ theories are valuable but are best applied together rather than individually. Let me know if you have any further questions.