What is the structure of the alcohol functional group?

The alcohol functional group is characterized by the presence of a hydroxyl group (-OH) attached to a carbon atom. In the structure provided, CH3-OH, the -OH group is clearly depicted, indicating that this compound is indeed an alcohol. The carbon is bonded to three hydrogens and one hydroxyl group, making it a simple alcohol known as methanol.

Understanding the structure of alcohols is crucial, as they play significant roles in various biochemical processes. They are polar, which allows them to interact with other polar molecules, and this property is critical for their functions in biological systems. Additionally, the presence of the hydroxyl group is what defines alcohols and distinguishes them from other functional groups.

The other options do not contain a hydroxyl group directly bonded to a carbon, which is necessary for a compound to be classified as an alcohol. For instance, acetic acid (the structure in the first option) includes a carboxyl group (-COOH) instead. The amine in the third option lacks the hydroxyl group, and the fourth structure is an alkane with no functional groups present. Thus, B is the only choice that accurately represents the structure of the alcohol functional group.