Which of the following are food preservatives?

Correct option is A

The correct answer is (a) salt, sodium nitrite, spices and vinegar.
 Salt, sodium nitrite, spices, and vinegar are commonly used food preservatives that help to inhibit the growth of microorganisms that spoil food. They are added to foods to extend their shelf life and maintain their quality.
 Gypsum, soda, methyl alcohol, and formic acid are not commonly used as food preservatives. Gypsum is a mineral used in the manufacturing of cement and plaster of Paris, soda is a leavening agent used in baking, methyl alcohol is a type of alcohol that can be toxic if ingested, and formic acid is primarily used in the production of leather and textiles.