Hint: Cucurbit is also called Cucurbitaceae, which is a gourd family, that consists of 965 species, most of the species are economically important to humans. Plants of such species are grown around the temperate and tropical regions.
Complete answer: Cucurbitaceae family have the highest number of plant species which is cultivated by humans, in Cucurbitaceae possess some chemical substance which gives a bitter taste to the fruit, the chemical substance is cucurbitacin and it is chemically classified as triterpenes. Triterpene is a hydrocarbon formed from unsaturated variant cucurbit-5-ene. The bitterness of the plant acts as a defense mechanism against herbivores. The derivatives are found in many plant families that include Brassicaceae, Begoniaceae, Rosaceae, Rubiaceae, and in some of the mushrooms. Cucurbitacin has a number of variants that range from cucurbitacin A to cucurbitacin T. The bitterness in cucurbits plants is influenced by some other factors such as environmental stress like temperature is too high or too low induce the bitterness in these plant species, and lack of water in such plant bodies also induced the bitterness. Cucurbitacin is present in different plants and their parts such as cucumber, zucchini, melon, and pumpkin. Cucurbitacin compounds show some other biological properties like toxicity and in some pharmacological industries for cancer, diabetes, inflammation, and cardiovascular disease. The toxicity is induced due to the high intake of cucurbitacins which cause toxic squash syndrome. Hence, the correct option is C.
Note: The concentration of cucurbitacin toxin is also influenced by cross-pollination with wild species of Cucurbitaceae species. Bi genes are responsible for the bitterness of the entire plant. Bitterness in fruit requires two genes such as the Bi and Bt genes.