The figure shown here relates to the flow of information from DNA to RNA to protein.Select the correct alternative scenario(s)for insertion of leucine instead of phenylalanine during translation.

A)Error prone RNA polymerase creates a mutant mRNA from a correct DNA template
B)Mutated tRNA introduces leucine instead of phenylalanine against the correct mRNA sequence
C)Mutated ribosome creates a environment where mRNA-tRNA mismatches occur infrequently
D)Both a and b are possible correct scenarios
E)All of these possibilities could explain the translational error