Final answer:
The subject of this question is Chemistry. Gas chromatography is a method used to analyze the components of a mixture based on their different affinities for an absorbent material.
Step-by-step explanation:
The subject of this question is Chemistry. The question is related to the analysis of ethanol in mouthwash using a specific technique called gas chromatography. Gas chromatography is a method used to separate and analyze the components of a mixture based on their different affinities for an absorbent material.