In RNA polymerase-directed transcription, during elongation, aspartyl residues (asp)along with Mg²⁺ ions coordinate the phosphates of the ribonucleotides. The overall reaction is (NMP)n +NTP → (NMP)n+1 +PPi. Which of the following is correct about the first and second Mg²⁺ ions?

• A. The first Mg²⁺ ion bonds with the pyrophosphate of NTP whereas the second Mg²⁺ bonds with the α-phosphate of NTP.
• B. The first Mg²⁺ ion bonds with α-phosphate of NTP whereas the second Mg²⁺ bonds with pyrophosphate of NTP.
• C. Mg²⁺ ions aren't involved in the elongation process.
• D. None of these.