1083 appreciation: 这里做理解的意思 [uncountable and countable] an understanding of the importance or meaning of something appreciation of a realistic appreciation of the situation
The best answer is D. In lines 14-16, the author of the passage describes the skepticism of Black workers toward unions, “which had historically barred Black workers from membership,” as “understandable,” thus conveying an appreciation that the attitude of Black workers had a legitimate basis.