Which is added to foods to prevent spoilage and increase shelf life?
a. pasteurization
b. preservative
c. irradiation
d. microorganism

The answer is letter B.

Preservatives are added to food to prevent its spoilage and to increase its shelf life. In our society, food is one of the many products that contain preservatives. You can also find them in medicines, paints, cosmetics, wood, among others. This is commonly done to prevent decay caused by microbial growth or chemical changes. It comes in two modes called chemical and physical preservation. Chemical preservation is when chemical compounds are added to products, like the one we find in a lot of foods. Physical preservation involves processing techniques like dehydration, freeze drying, and refrigeration.

The correct answer is "grounded".