Fuel X gives carbon dioxide and water when it is combusted in air. Fuel Y does the same. What might X and Y be?
- A$X = \text{C},\ Y = \text{H}_2$
- B$X = \text{C},\ Y = \text{C}_8\text{H}_{18}$
- C$X = \text{CH}_4,\ Y = \text{H}_2$
- D$X = \text{CH}_4,\ Y = \text{C}_8\text{H}_{18}$