Which of the following methods is used in food preservation for a long period?

Salting and drying the food is a method used in food preservation for a long period. Salting and drying is an ancient method of food preservation that involves removing the moisture from food, which inhibits the growth of bacteria and other microorganisms that cause food to spoil. Salt acts as a preservative by drawing moisture out of the food and creating an environment that is inhospitable to bacteria. Drying the food complements the preserving effects of salt by reducing the water content to a level where microorganisms cannot survive. This method has been used for centuries to preserve a wide variety of foods, including fish, meat, and fruits. Once the food is salted and dried, it can be stored for months or even years without spoiling. Therefore, of the options given, salting and drying the food is the method used in food preservation for a long period.