Cracking an alkane, $X$, gives methane, ethene and propene as the products. The mole fraction of ethene in the products is $0.5$. What is the identity of $X$?
- A$\text{C}_6\text{H}_{14}$
- B$\text{C}_8\text{H}_{18}$
- C$\text{C}_9\text{H}_{20}$
- D$\text{C}_{11}\text{H}_{24}$