The major constituent of soda lime glass is option 4, Silica. Soda lime glass is a type of glass that is commonly used in windows, bottles, and various household items. It is made by melting a mixture of silica (silicon dioxide), sodium oxide, and calcium oxide.

Option 1, Sodium oxide, is a component of soda lime glass but it is not the major constituent. Sodium oxide helps to lower the melting point of the glass and improve its durability.

Option 2, Calcium oxide, is also a component of soda lime glass but again, it is not the major constituent. Calcium oxide acts as a flux and helps to stabilize the glass during the melting process.

Option 3, Calcium carbonate, is not a correct answer. While it does contain calcium, it is not directly used in the production of soda lime glass.

In summary, the correct answer is option 4, Silica, as it is the main component of soda lime glass.