Dan Is an Alcoholic Who Has Been Drinking Large Amounts

Dan is an alcoholic who has been drinking large amounts of alcohol for more than a decade. Ed, a social drinker, drinks moderately at parties and has never been "drunk." For a research study, each of these 150-pound men consume eight beers in a few hours. Dan does not seem to be affected, whereas Ed exhibits major effects. How can we explain this difference?

A) The liver of an alcoholic breaks down alcohol into byproducts much faster because it has adjusted to high levels of alcohol and this rapid breakdown aids survival.
B) As a protective device, the body of an alcoholic diverts most of the alcohol away from the brain so it does not have the effect it does in someone who is not an alcoholic.
C) Over long periods of time, neurotransmitter levels in the brain adjusts to a relatively steady state of alcohol and remain constant, so the amount of alcohol has practically no effect.
D) In someone who has been drinking excessively for a long time, less and less alcohol permeates brain cell membranes so he may have less alcohol in his brain than someone with the same BA level who is not an alcoholic.