The correct answer is Vitamin C.Concept:Vitamins are organic substances that we need in sufficient quantities to maintain good health.Our body, however, cannot synthesize them. Therefore, we need to consume natural sources such as fruits and vegetables.Vitamins are divided into two groups‚¬€œ water-soluble vitamins (Vitamins of B group and Vitamin C) and fat-soluble vitamins (Vitamins A, D, E, and K).Explanation:Vitamin C is the vitamin that is destroyed by heat during cooking. When we boil something that contains vitamin C, it reduces its content more than any other method of cooking.Broccoli, spinach, and lettuce, for example, lose up to or more than 50% of their vitamin C when they are cooked.Water-soluble vitamins are also temperature-sensitive vitamins.When the temperature drops below 860F, vitamin C begins to denature. Vitamin C is primarily found in oranges, strawberries, tomatoes, broccoli, and green peppers, among other fruits and vegetables. When vitamin C is exposed to air, it is easily destroyed, which is what happens when food is overheated.When fat-soluble vitamins are heated or exposed to air, they are not destroyed.