Final answer:
Consuming alcohol quickly on an empty stomach can lead to a rapid increase in BAC.
Step-by-step explanation:
One can have a rapid increase in BAC by consuming alcohol quickly on an empty stomach. When alcohol is consumed quickly, it is rapidly absorbed into the bloodstream, leading to a higher concentration of alcohol in the blood. Having an empty stomach also allows the alcohol to be absorbed more quickly as there is no food to slow down the process.