The properties of four fuels are listed below. Which fuel is a gas at room temperature and produces two substances when it burns in an excess of air?
- Ahydrogen, $\text{H}_2$, melting point $-259\,^\circ\text{C}$, boiling point $-253\,^\circ\text{C}$
- Bmethane, $\text{CH}_4$, melting point $-182\,^\circ\text{C}$, boiling point $-164\,^\circ\text{C}$
- Coctane, $\text{C}_8\text{H}_{18}$, melting point $-57\,^\circ\text{C}$, boiling point $126\,^\circ\text{C}$
- Dwax, $\text{C}_{31}\text{H}_{64}$, melting point $60\,^\circ\text{C}$, boiling point $400\,^\circ\text{C}$