Despite the political pressure
on country clubs to allow women and minorities to join, they have maintained a policy that prevents membership by these groups.
(A) on country clubs to allow women and minorities to join, they have maintained a policy
------> "they" is quite ambiguous
(B) to allow women and minorities to join country clubs, a policy has been maintained
---> pressure should be used with prep "on"
(C) on country clubs to allow the joining of women and minorities, the clubs have maintained a policy
-----> correct prep and eliminate the ambiguous "they" --->fine
(D) to allow women and minorities to join country clubs, they have maintained a policy
----> problem with "they"
(E) on country clubs to allow the joining of women and minorities, they have maintained a policy
----> also problem with "they"
I would go for B