A 1000 base pair double-stranded DNA (B form) has a melting temperature $\left(T_m\right)$ of $58^{\circ} \mathrm{C}$. If a duplex RNA (A form) of the same length and sequence is constructed, then the $T_m$ of this new RNA duplex with respect to the DNA (B form) would be

• Correct answer
  A

  higher due to greater stability of A form of RNA duplex.
• B

  lower due to lower stability of A form of RNA duplex.
• C

  lower because of unfavourable enthalpy of formation of RNA duplex.
• D

  identical, as the number of hydrogen bonds remain the same.

Hence, the correct answer is option: 'A'.