Answer: The correct answer is A) TAC.
Start codon is the first codon (sequence of three nucleotides) in the mRNA (messenger RNA) transcript from where the process of protein synthesis (translation) is initiated.
m RNA is formed using a template of DNA that is complementary to it.
For Thymine (T) in the DNA template, Adenine (A) is added in the mRNA and for Adenine (A), Uracil (U) is added in the mRNA.
Similarly, for Guanine (G), Cytosine is added in the mRNA and vice versa.
Therefore, corresponding to AUG in the mRNA, TAC sequence is present in the DNA.