Which class includes an unsaturated hydrocarbon with a ring structure?

The correct answer is aromatic hydrocarbons.

Explanation:

Aromatic compounds are named on the basis of their fragrant characteristics and are unsaturated hydrocarbon ring compositions, which demonstrate unique characteristics, comprising unusual stability because of their aromaticity.  

They are usually signified as resonance compositions comprising double and single bonds. However, the bonding is more robust in comparison to a conjugated structure, and it is more precisely signified as delocalized electron density shared among all the atoms in the ring.  

he uptake of drugs from the intestine is often strongly influenced by diffusion. for example, consider a water-insoluble steroid for treating inflammation that is solubilized in aggregates of detergent molecules, called micelles. these micelles, aggregates of 80 soap molecules, have a molecular weight of 24,000, a diameter of 2.6 nm, and a charge of -27. the positively charge ions (counterions) in this system are na".

i think that the answer is c