Why might two people have different BAC after consuming the same amount of alcohol?

• A. Because of different snacks.
• B. Rate of consumption, gender, body size, and amount of food in the stomach.
• C. Because one person owns a larger bottle.
• D. Because BAC is the same for everyone.

Answer: (B)

BAC after the same amount of alcohol can differ because how alcohol moves through and sits in the body isn’t the same for everyone. The best explanation includes four main influences: how quickly the alcohol is drunk (rate of consumption), gender, body size, and how much food is in the stomach.

Drinking quickly means more alcohol enters the bloodstream before the liver can metabolize it, so BAC rises higher. Gender matters because, on average, women have less body water and usually lower levels of stomach enzymes that start breaking down alcohol, so a larger fraction reaches the bloodstream. Body size also plays a role: larger people typically have more body water to dilute alcohol, leading to a lower BAC for the same amount consumed. Finally, having food in the stomach slows alcohol absorption, so peak BAC is lower if you’ve eaten.

The other options don’t capture these combined effects. Snacking alone isn’t the primary determinant, one person’s bottle size doesn’t set BAC, and BAC isn’t the same for everyone.