Combustible substance: Substances that burn easily or catch fire easily are called combustible substances.
Paper, clothes, wood, LPG are all combustible substances. Without these substances, a fire cannot be started.
1. Camphor is a waxy, flammable, white or transparent solid with a strong aromatic odour and combustible material.
2. Glass consists mostly of oxides such as silica. Because the elements are in their highest oxidation states, they will not react with oxygen. Thus, glass is not combustible.
3. Alcohol is a hydrocarbon, especially the ones with low molecular mass, are very combustible. They combine with oxygen readily and make carbon dioxide and water. If there is not enough oxygen, they can also make some carbon monoxide.
Hence the correct option is B.