Which of the following sentences includes a weak verb-noun combination that makes the sentence less concise?

a) although roberta lives in california, she plans to go to college in pennsylvania.
b) for this essay i will conduct a study of bees and the arrangement of their colonies.
c) the government can't even offer proof that any terrorist attack has been prevented by secretly sweeping all american phone data.
d) the candidate spoke passionately about the need to eliminate college grants and other social programs.