Which of the following is heterocyclic aromatic compound?

Step-by-step solution

A compound is considered aromatic if it is cyclic, planar, completely conjugated, and satisfies Hückel's rule by having (4n + 2) electrons. Let us examine each option: Option (1): The structure is a pyrylium ion. It is a six-membered heterocyclic ring containing an oxygen atom. The oxygen atom carries a positive charge and is sp^2 hybridized. There are three double bonds in the ring, contributing 6 electrons. The molecule is cyclic, planar, fully conjugated, and has 6 electrons ( n=1 in Hückel's rule). Therefore, i