Answer:
So I think you're trying to ask where transcription errors take place, which I would say is A.
Step-by-step explanation:
DNA transcrption is when DNA is converted to RNA, which is then sent to ribosomes in the cell to make specific protiens(this is how viruses destroy cells, they use this system to make more viruses by causing viral RNA or DNA(transcripted)to be given to ribosomes) Anyway, transcritpion makes certain sequences of Amino acids for protiens, so an error is going to affect this area first, which can cause large systematic problems later.