Which of the following fruit is a single seeded nut

Answer: Option A

Litchi is a single-seeded nut from the given options.
Litchi is a subtropical fruit tree of the family Sapindaceae with great economic and nutritional value. Based on fruit anatomy, the fruit of litchi is a drupe with an edible aril enclosing a single seed surrounded by a pericarp.
The fruit is a one-seeded nut, develops in bunches and varies in shape and size. The edible portion of litchi called an aril lies under the papillate, pinkish-red pericarp and surrounds the dark-brown, oily-skinned seed.