Cell membrane is the answr
I think the most suitable answer is carbohydrates as it can be monosaccharide, disaccharide or polysaccharide.
In the text it says “Most macromolecules are made from single subunits, or building blocks, called monomers. The monomers combine with each other using covalent bonds to form larger molecules known as polymers. In doing so, monomers release water molecules as byproducts. ... In the process, a water molecule is formed.” I hope this helped
It depends on your teacher, it should be A. It could be B if that’s what your teacher wants but I would go with A.