Final answer:
The passage of time is the only effective way to lower BAC since only the liver can metabolize alcohol, and other common methods such as drinking coffee or taking showers do not expedite this natural process.
Step-by-step explanation:
The only effective method to reduce your Blood Alcohol Concentration (BAC) is c) The passage of time. This is because your liver needs sufficient time to process and metabolize the alcohol in your system. Misconceptions such as drinking coffee, eating a heavy meal, or taking a cold shower do not speed up this process. After drinking ceases, the alcohol excretion rate and liver metabolism determine how long it takes for one's BAC to return to safe levels. It can take at least five hours for a legally intoxicated individual (BAC of 0.08) to reach sobriety.