Final answer:
The organ in the body where most alcohol is metabolized is the liver (Option 4).
Step-by-step explanation:
The liver processes up to 85% - 98% of the ethanol present in the bloodstream utilizing primarily the alcohol dehydrogenase system to convert ethanol into acetaldehyde, which is subsequently transformed into less toxic compounds such as acetate.
It is crucial for the liver to fully metabolize ingested alcohol to prevent alcohol toxicity; other measures like drinking coffee or taking a shower do not expedite this process. The liver's function of breaking down alcohol into carbon dioxide and water highlights its critical role in managing substances that could potentially be harmful to the body.
While other organs, such as the kidneys, are part of the excretory system and help remove waste, they do not play a primary role in alcohol metabolism. For individuals who engage in heavy drinking, the microsomal ethanol oxidizing system (MEOS) can increase its capacity to metabolize excess ethanol, yet it is the liver's alcohol dehydrogenase system that handles the majority of alcohol metabolism normally.
Thus, the correct option is number 4.