Name the hydrocarbon having the poorest oxidation stability.

Answer: Option B

In petroleum refinery engineering, aromatics are the hydrocarbons having the poorest oxidation stability.

Aromatics, such as benzene, toluene, and xylene, contain one or more benzene rings in their molecular structure. These compounds are highly reactive and prone to oxidation, which can lead to the formation of harmful by-products and degradation of the petroleum product's quality over time.

Therefore, the correct option is Option D: Aromatics.