Rearrange the following stages of anaerobic degradation of wastes in landfills in the correct order:
1. Methanogenic bacteria convert acetic acid into methane and carbon dioxide.
2. Hydrolysis and fermentation of solid organic components.
3. Conversion of volatile fatty acids into acetic acid.
1
2, 3, 1
2
3, 2, 1
3
1, 2, 3
4
2, 1, 3