Final answer:
In the provided options, fat and folate are organic nutrients, as they are carbon-containing compounds essential to the body's diet. Phosphorous is a nutrient stored in the body, and vitamin C is an example of a water-soluble vitamin that must be obtained through the diet. Therefore, the correct option is A and B.
Step-by-step explanation:
The student asked which of the listed items is an organic nutrient, with options including fat, folate, calcium, and selenium. Out of these, fat and folate are organic nutrients. Fats are organic molecules composed of carbon, hydrogen, and oxygen, and are an important component of cell membranes and a source of energy. Folate, also known as vitamin B9, is a water-soluble B vitamin essential for the body's metabolic processes.
In the context of nutrition, an organic nutrient typically refers to a compound that contains carbon and is essential in the diets of some organisms. Vitamins and fats are examples of organic nutrients. Minerals like calcium and selenium, on the other hand, do not contain carbon and are considered inorganic nutrients.
Regarding storage in the body, phosphorous is one of the nutrients that can be stored in the body, being a major component of bones and teeth. For water-soluble vitamins, vitamin C is an example; it must be regularly supplied in the diet because excess amounts are not stored in the body. Finally, essential nutrients like vitamins must be obtained through dietary sources as they are not synthesized by the body but are necessary for proper function, with vitamin A and K being fat-soluble vitamins.