What is one particular function that the codons (UAA, UGA, or UAG) serve during protein synthesis? Select one: a. UAA, UGA, and UAG are initiator codons, not termination codons. b. They act in chain termination. c. They provide a substrate for the addition of the initiator amino acid. d. These triplets cause frameshift mutations, but are not involved in termination e. They allow the mRNA to assume a variety of linear conformations.