Based on Bohr's atomic model:
- A. Radius of electron orbit: The radius of an electron’s orbit is directly proportional to \(n^2\). Therefore, the match is A-I.
- B. Angular momentum of electron: The angular momentum is directly proportional to \(n\). Therefore, the match is B-II.
- C. Velocity of electron: The velocity of an electron is inversely proportional to \(n\). Therefore, the match is C-III.
- D. Energy of electron: The energy is inversely proportional to \(n^2\). Therefore, the match is D-IV.