Final answer:
Dairy products are not a good source of manganese, unlike nuts, legumes, and green leafy vegetables which are rich in this essential mineral.
Step-by-step explanation:
The correct answer to the question 'Which of the following is not a good source of manganese?' is b. Dairy products. While nuts, legumes, and green leafy vegetables are all good sources of manganese, dairy products are not known to be significant sources of this mineral. Manganese is essential for many body functions, including the metabolism of amino acids, cholesterol, glucose, and carbohydrates. Nuts, legumes, and green leafy vegetables are rich in manganese and can help fulfill the body's requirements for this essential nutrient.