The correct option is C Groundnut
Geocarpic fruit is a ground nut. Geocarpic means producing or ripening the fruit beneath the surface of the ground like the peanuts. Peanut has another name specific name, Hypogaea which means under the earth, after pollination, the flower stalk elongates, causing it to bend until the ovary touches the ground. Continued stalk growth then pushes the ovary underground, where the mature fruit develops into a legume pod, the peanut a classical example of geocarpy.
Thus, the correct answer is option C.