The answer to this question is the Pyers
patches. The Pyers patches are lymphatic tissues found through
the small intestines that have an important role in the immune system. Pyers
patches are also known as the aggregated lymphoid nodules that monitors and
prevents growth of bacteria in the intestine that is harmful in the intestines.
It would be A. Iron & Nickel.
Hope it helps you!:)
<span>The significance of chitin in arthropods is Chitin is a structural carbohydrate that forms their exoskeleton. </span>
Carbon dioxide is used to build sugars. I think it's the only one