The sequence below corresponds to the first 15 bases of the open reading frame of the E. coli cysS gene. For each of the following mutation sequences, determine the amino acid sequence encoded by the 15 bases, identify whether the mutation is a transition, transversion, insertion, deletion. Also identify whether the mutation is a missense, nonsense, silent or frame-shift mutation. 5' ATG CTA AAA ATC TTC a. 5' ATG CTA AAG ATC TTC b. 5' ATG CTA TAA ATC TTC c. 5' ATG CTA AAA AAT CTT d. 5' ATG CGA AAA ATC TTC