Concept:Protein synthesis involves translation, where ribosomes move along mRNA and tRNA molecules add amino acids.Explanation:During elongation, the ribosome translocates along the mRNA strand. This exposes the next codon on the mRNA. A tRNA with a complementary anticodon base-pairs with this codon. This tRNA carries the specific amino acid needed for the growing protein chain. Therefore, option B best describes protein synthesis.Answer:B