A. The matter was informed to the police.
B. The matter has been informed of the police.
C. The police was informed of the matter.
D. The police were informed of the matter.
The police refers to a group and requires a plural verb, so option 'D' should be the correct answer out of option 'C and D'. But, I don't understand what's wrong with option 'A and B'. Is there anything to do with the prepositions after the verb inform? Should it be 'informed of or informed to'?