Identifying Aromatic Compounds

Aromatic compounds are a category of organic compounds characterized by the presence of one or more benzene rings in their structure. Benzene is known for its stability and unique reaction patterns due to its conjugated pi electron system. One of the simplest examples of an aromatic compound is toluene, which consists of a benzene ring with a methyl group (–CH₃) attached. Understanding the properties and behaviors of aromatic compounds is crucial for various applications in chemistry and biology.

Which of the following is considered an aromatic compound?