A molecule of an alkane with molecular formula $\text{C}_8\text{H}_{18}$ is cracked. The reaction equation is given as $\text{C}_8\text{H}_{18} \rightarrow Q + 2R$. Substance R contains two carbon atoms in each molecule and turns aqueous bromine colourless. What is substance Q?
- Abutane
- Bbutene
- Cethane
- Dethene