This question is about hydrocarbons.
The structures of hydrocarbons A–E are shown below:

Which hydrocarbons are unsaturated?
Which hydrocarbons are alicyclic?
Which hydrocarbons have the general formula CnH2n\text{C}_n\text{H}_{2n}CnH2n?
What is the systematic name of hydrocarbon C?
Explain why hydrocarbon D is an EEE-stereoisomer.