Final answer:
The number of essential nutrients classified into the 45 essential nutrients is most likely 5. Option a.
Step-by-step explanation:
The question asks about the number of essential nutrients classified into the 45 essential nutrients. The six major classes of nutrients based on biochemical properties are carbohydrates, proteins, lipids, water, vitamins, and minerals. Among these, water and fiber are considered essential nutrients. Although specific numbers are not provided, it can be inferred from the information given that the answer is most likely option a) 5.
In response to the question about how many essential nutrients there are, there are more than 45 essential nutrients classified into these categories. The answer choices provided in the question do not accurately reflect current knowledge on the number of essential nutrients required by the human body. However, it's important to note that the essential nutrients must be obtained through a balanced diet as they are critical for survival and the body does not produce them in adequate quantities.