What is the structure of benzene?

Benzene is accurately described as a six-carbon ring that has alternating double bonds. However, it's essential to note that in reality, benzene does not have distinct single or double bonds due to resonance structures. Instead, it has a delocalized pi electron cloud that allows for equal bond lengths and strengths between all the carbon-carbon connections, which gives benzene its unique stability and properties.

The structure of benzene is often depicted as a hexagon with a circle inside it, representing this electron delocalization. The resonance forms show that the actual structure is a hybrid of these configurations, contributing to the compound's stability. Therefore, the correct option highlights the alternating double bonds as a representation of this delocalization, despite the more accurate description being that all the bonds are equivalent.

Other options, such as a hexagonal ring with single bonds only, misrepresent benzene’s bonding nature, while a linear chain of six carbons fails to capture the cyclic structure and aromatic character that benzene possesses. The last option describes a five-membered ring, which does not apply to benzene at all.