Which of the following best explains why a variety of monomers are needed to produce the complex molecules necessary for life? different monomers contain different kinds of atoms needed to produce different end products. all monomers contain the same kinds of atoms, but their unique structures result in different end products. different monomers contain different amounts of energy needed to initiate product formation. all complex molecules are formed from nucleotides, but other kinds of monomers are needed to produce energy.