- Silica (sand) is the primary component, forming the glass structure. - Sodium carbonate (soda ash) is added to lower the melting point of silica. It decomposes to sodium oxide (Na₂O) during heating. - Calcium carbonate (limestone) is added to improve durability and prevent the glass from dissolving in water. It decomposes to calcium oxide (CaO) during heating. - Alumina (aluminium oxide) is a common additive to increase strength, chemical resistance, and reduce devitrification. - Borax (sodium borate) is used in the manufacture of borosilicate glass, which has high thermal resistance. Its presence in option A suggests a broader view of glass manufacturing ingredients beyond just standard soda-lime glass. - Cullets are recycled glass added to the batch mixture. They act as a flux, reducing the melting temperature and saving energy.