When $2$ moles of a straight chain alkane undergo complete combustion, $400\,\text{dm}^3$ of carbon dioxide are produced, with the gas volume taken at $301\,\text{K}$ and $1 \times 10^5\,\text{Pa}$. It may be assumed that carbon dioxide behaves ideally under these conditions. Determine the formula of the straight chain alkane.
- A$\text{C}_8\text{H}_{18}$
- B$\text{C}_{16}\text{H}_{34}$
- C$\text{C}_{20}\text{H}_{42}$
- D$\text{C}_{40}\text{H}_{82}$