Alcohols are the compounds containing hydroxyl group attached to the alkyl group, whereas phenols are hydroxyl derivatives of aromatic hydrocarbons in which hydroxyl group is directly attached to carbon atom of aromatic ring. Alcohols are versatile compounds and can behave both as nucleophiles as well as electrophiles.
Phenols, too are reactive compounds and are known to undergo reactions on : phenolic group, benzene ring as well as various other name reactions like Reimer-Tiemann reaction, Kolbe's reaction etc.

Which of the following is the correct structure of Aspirin?

The correct answer is option 3.

Aspirin or Acetylsalicylic acid has an empirical formula of \(C_9H_8O_4\). The molecular geometry of aspirin is planar and its molecular mass is 180.159 g/mol. The structural formula of aspirin or Acetylsalicylic acid is represented as:

Aspirin is extensively used in the pharmaceutical sector. The most common way to prepare aspirin is by using Acid Anhydrides and by reacting acetic acid with salicylic acid.