Answer:
C. a stop codon is reached.
Explanation:
Translation is the process by which proteins are synthesised from mRNA. It ends in the termination stage when a stop codon is encountered. Normally during translation the A-site of ribosome is responsible for binding the complementary codon on the mRNA with the incoming tRNA. The tRNA with the polypeptide chain is hold by the P-site.
During termination, a stop codon ( UAA, UGA or UAG) is encountered by the A site in ribosome and is then recognised by release factors. Release factors enter the P site and fit there leading to disassembly of entire ribosome/mRNA complex. A water molecule is added to the last amino acid of the chain which separates it from the tRNA molecule and leads to its release.
