The flow diagram illustrates the preparation of ethanol and several important reactions of ethanol. substance X $\xrightarrow{\text{fermentation}}$ ethanol $\xrightarrow{\text{process Y}}$ carbon dioxide + substance Z Identify X, Y and Z.
- AX: yeast, Y: combustion, Z: oxygen
- BX: glucose, Y: combustion, Z: steam
- CX: glucose, Y: polymerisation, Z: water
- DX: yeast, Y: fermentation, Z: glucose