Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 30 to 34.

In addition to providing energy, fats have several other functions in the body. The fat soluble vitamins, A, D, E and K, are dissolved in fats, as their name implies. Good sources of these vitamins have high oil or fat content, and the vitamins are stored in the body's fatty tissues. In the diet, fats cause food to remain longer in the stomach, this increasing the feeling of fullness for some time after a meal is eaten. Fats add variety, taste, and texture to foods, which accounts for the popularity of fried foods. Fatty deposits in the body have an insulating and protective value. The curves of the human female body are due mostly to strategically located fat deposits.

Whether a certain amount of fat in the diet is essential to human health is not definitely known. When rats are fed a fat-free diet, their growth eventually ceases, their skin becomes inflamed and scaly, and their reproductive systems are damaged. Two fatty acids, linoleic and arachidonic acids, prevent these abnormalities and hence are called essential fatty acids. They also are required by a number of other animals but their roles in human beings are debatable. Most nutritionists consider linoleic fatty acid an essential nutrient for humans. 

Linoleic fatty acid is mentioned in the passage as 

A. an essential nutrient for humans 

B. more useful than arachidonic acid 

C. preventing weight gain in rats 

D. a nutrient found in most food