A group of friends is heading to an evening event where alcohol will certainly be served. What is the most reliable way to make sure nobody drives impaired afterwards?

Why D is correct

Impaired judgement is the defining product of alcohol, which is why the decision about driving cannot be delegated to the end of the evening, when judgement is exactly what is compromised. The designated driver arrangement works because it is made sober, before any drinking starts, and its whole value depends on the designated driver actually abstaining — a person on their third drink is a designated drinker, not a designated driver. Every fallback plan that relies on self-assessment at closing time relies on the one faculty alcohol is measurably removing.

Why the other options are wrong

A. Plan to drink coffee and water in the final hour before driving home

Coffee restructures a drunk into an awake drunk. Water and coffee change none of the alcohol waiting in the bloodstream, and the 'final hour' plan is a well-known failure because it treats sedation as if it were dehydration.

B. Rely on everyone monitoring their own condition and stopping at two drinks each

Self-monitoring fails at the exact moment it is needed. The research and the crash data agree: impairment begins well before the drinker detects it, and counting drinks is a record of consumption, not of the blood alcohol the drinks produced two hours later.

C. Agree that whoever feels least affected at the end of the night will drive

Ranking the group by perceived impairment at the end of the night selects the least-drunk driver available, not a sober one. The comparison everyone makes in that moment is between impaired people, and the winner of that comparison still drives impaired.

On the road

Before the first round is ordered, Nadia hands over her car keys and claims the water glass for the night. At midnight the rest of the table debates who is 'fine' — the debate Nadia's morning self settled at seven o'clock. Four people ride home with a sober driver, and the argument that never happened is the entire return on one early decision.

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