When some marble chips (calcium carbonate) are heated strongly, substances $X$ and $Y$ are produced. Substance $X$ is a white solid which reacts with water and releases heat. Substance $Y$ is a colourless gas. What are substances $X$ and $Y$?
- A$X$: calcium chloride, $Y$: oxygen
- B$X$: calcium hydroxide, $Y$: carbon dioxide
- C$X$: calcium oxide, $Y$: carbon dioxide
- D$X$: calcium sulfate, $Y$: oxygen