Which of the following best describes a secondary alcohol?

A secondary alcohol is characterized by the presence of an -OH (hydroxyl) group attached to a carbon atom that is bonded to two other carbon atoms. This arrangement means that the carbon bearing the hydroxyl group is invested in a carbon framework where it is not on the end of the carbon chain (which would be a primary alcohol), and it certainly is not bonded to three carbons (which would define a tertiary alcohol).

In essence, when identifying secondary alcohols, consider the connectivity of the carbon that holds the hydroxyl group. If it is linked to two other carbons, it fits the definition of secondary alcohols. This structural characteristic is essential for distinguishing between the different classifications of alcohols, affecting their chemical behavior and properties. That is why the correct answer accurately describes secondary alcohols in the context of organic nomenclature.