Which one of the following is the permanent method of preservation of fruits and vegetables?

Answer: Option D

Exclusion of moisture is the permanent method of preservation of fruits and vegetables.
Drying is the method of preservation of fruits and vegetables usually practiced in homes. Drying is done to remove moisture from the fruits and vegetables that reduce the chances of rotting and ant microbial activity. Thus it enables us to keep it and used it later whenever required in off season also.