The correct answer is C. DNA
Explanation:
In cells, thymine can be found in the DNA or Deoxyribonucleic Acid because this is thymine is a nucleobase, which is an essential substance for DNA's structure. Moreover, thymine differs from other nucleobases such as guanine or adenine because other nucleobases can also be found in RNA or Ribonucleic acid but thymine is exclusive of DNA. In this context, the molecules that will be radioactively labeled in this case is DNA (Option C).
