Final answer:
The only thing that lowers a person's BAC is time.
Step-by-step explanation:
The only thing that lowers a person's BAC (blood alcohol concentration) is time.
When a person drinks alcohol, their BAC rises. However, the body gradually metabolizes and eliminates alcohol over time, bringing the BAC back down to zero.
Eating a meal, drinking water, sleeping, and exercising may help a person feel better or more sober, but they do not lower the BAC itself.