What does BAC not depend on?

Answer: C — How fit you are

Blood Alcohol Concentration (BAC) is primarily influenced by the amount of alcohol consumed, the individual's body weight, metabolism, and how quickly the body processes alcohol. Factors such as age and weight directly affect how alcohol is absorbed and metabolized. While physical fitness might have some indirect effects on overall health and metabolism, it does not directly determine BAC levels when consuming the same amount of alcohol. Therefore, the correct answer highlights that BAC is not determined by how fit a person is. The type of alcohol consumed can also play a role in the rate of consumption and absorption, making it relevant to BAC calculations.