Sentence Correction

Some people are of the opinion that the police is incapable of curbing crime successfully because they have limited power.

(A) the police is incapable of curbing crime successfully because they have limited power.
(B) because the police have limited power, they are incapable of curbing crime successfully.
(C) the police are incapable of curbing crime successfully because they have limited power.
(D) the police, because it has limited power, is incapable of curbing crime successfully.
(E) having limited power, the police is incapable of curbing crime successfully.

what do you think about option A and C. which do you agree with as the correct option and why is it so?