The diagram shows part of a polymer chain. Which alkene was used to produce this polymer?
- A$\text{CH}_3\text{CH} = \text{CH}_2$
- B$\text{CH}_3\text{CH}_2\text{CH} = \text{CH}_2$
- C$\text{CH}_3\text{CH}_2\text{CH} = \text{CHCH}_3$
- D$\text{CH}_3\text{CH} = \text{CHCH}_3$