请教885 sec03-09

9.     In the United States, trade unions encountered far more intense opposition against their struggle for social legitimacy than the organized labor movements of most other democratic nations.

(A) against their struggle for social legitimacy than

(B) in their struggle for social legitimacy than did

(C) against their struggle for social legitimacy as

(D) in their struggle for social legitimacy as did（B）

(E) when they struggled for social legitimacy than has

请问than did没有错吗？trade unions 是和the organized labor movements of most other democratic nations做比较，最多应该写成than the organized labor movements of most other democratic nations did???

我这点比较弱，想不通，讨论帖中也没有相关解释，还请各位帮帮忙，谢谢！

我这点比较弱，想不通，讨论帖中也没有相关解释，还请各位帮帮忙，谢谢！