Final answer:
Essential fatty acids, which include omega-3 and omega-6 fatty acids, are necessary components of the diet as they cannot be synthesized by the body and are important for cellular functions. The correct answer is b.
Step-by-step explanation:
Essential fatty acids are fatty acids that are necessary for the proper functioning of the body but cannot be synthesized by the body, so they must be obtained from the diet. These fatty acids play important roles in various physiological processes, including maintaining the structure and function of cell membranes, supporting the nervous system, and contributing to overall health. Common examples of essential fatty acids include omega-3 and omega-6 fatty acids. Options (a), (c), and (d) do not accurately describe essential fatty acids. Hence the correct answer is b.