The correct option is C Cashewnut
Nuts are simple, dry, one chambered (unilocular), one seeded fruits. Nuts develop from a bicarpellary or multicarpellary syncarpous (united carpels) ovary. Pericarp or the fruit wall is hard and woody. Example: Cashew nut, litchi, oak nut, etc.
Coconut is a drupe which develops from monocarpellary superior ovaries and is one seeded.
Groundnut is an example of a simple fruit that is dry and indehiscent.
Areca nuts are the seed of a fruit called berry. Berry is a small pulpy and edible fruit. Berry is a fruit produced from mono or multicarpellary syncarpous gynoecium. The fleshy pericarp has outer thin epicarp. The mesocarp and endocarp have fused to become the fleshy pulp in which the seeds are embedded. Example: Grape, brinjal, tomato.