The diagram illustrates the production of a gas, G, through four reactions, starting from glucose or from a solid, S. What are the formulae of gas G and solid S?
- Agas G: $\text{CH}_4$, solid S: $\text{Ca}$
- Bgas G: $\text{CH}_4$, solid S: $\text{CaCO}_3$
- Cgas G: $\text{CO}_2$, solid S: $\text{Ca}$
- Dgas G: $\text{CO}_2$, solid S: $\text{CaCO}_3$