It would be c. It can bond with other atoms through ionic and covenant bonds.<span />
Answer:
Animal by-products.
The USDA (United States Department of Agriculture) defines an animal product as anything made from an animal, excluding muscle meat.
Three scientists are credited with the development of cell theory. Matthias Schleiden observed that all plants were made of cells; Theodor Schwann observed that all animals were also made of cells; and Rudolf Virchow observed that cells only come from other cells.
The answer, I believe, is all of the above.
Hope this helps!!