Several young men and women decide to spend a fall weekend on a houseboat on the lake. They devote Saturday to swimming, eating, and drinking. The drinking continues late into the night. Bill, Joan, and a few others engage in a drinking game to see who can drink a six-pack of beer the fastest. Joan wins the contest and soon falls asleep. She doesn't respond when Bill attempts to awaken her. Meanwhile, two women who did not participate in the drinking game, but who have been drinking, decide to swim in the lake. They laugh when someone says it might not be safe to get into the water, but they agree to put on life jackets and to stay within the boundaries of the boat's spotlight. Which of the following poses the greatest risk to the women who want to go swimming?
a. a nasty hangover
b. alcohol poisoning
c. disorientation
d. swimming injuries