Regarding the Reduction of the Impact of Moral Hazard by Insurers

Regarding the reduction of the impact of moral hazard by insurers, which of the following is true?

A) It is not possible for insurers to reduce the risk of moral hazard, and this is seen as a risk of doing business.
B) Insurers refuse to pay claims believed to result from the effects of moral hazard.
C) The only avenue for insurers seeking to reduce moral hazard is through the use of deductibles.
D) The only avenue for insurers seeking to reduce moral hazard is through refusing to insure those who have previously made multiple insurance claims.
E) Insurance companies lessen the impact of moral hazard by requiring that individuals with insurance make co-payments or pay a deductible.