Amino acids are Proteins,
Lipids are Fatty acids
Nucleic acid which have nucleotides and, build RNA and DNA
Starches are a cause of Carbohydrates, after lots of Polymers.
So, therefore the answer is a)
When water in a river or stream moves quickly, it can lift up rocks from the bottom of that body of water. When the rocks drop back down they bump into other rocks, and tiny pieces of the rocks break apart
