The compound 2-methylpropene, $\text{C}_4\text{H}_8$, is a monomer that is used to make synthetic rubber. Apart from 2-methylpropene, there are $x$ more isomers of $\text{C}_4\text{H}_8$ that have a double bond, whether they are structural isomers or otherwise. Determine the value of $x$.
- A1
- B2
- C3
- D4