Which one is correctly matched with its specificity for an amino acid, start or stop in protein synsis?

Codons are the nucleotide base triplets that specify a particular amino acid in proteins. The codons that do not code for any amino acid and cause termination of protein synthesis are known as stop codons. The RNA stop codons are UAG, UAA and UGA; option B is wrong. The start codon specifies the first codon of mRNA transcript that is translated by a ribosome. It codes for methionine in eukaryotes and a modified Met in prokaryotes. "AUG" is the most common start codon which makes option A wrong. The triplet UGU codes for cysteine, UAC codes for tyrosine, UCG codes for serine and UUU codes for phenylalanine. Option C is incorrect and D is correct.