$A$ hydrogen atom,a deuteron atom,a $He^+$ ion,and a $Li^{++}$ ion each contain a single electron orbiting their nucleus. The wavelengths of the electromagnetic radiation emitted during the transition of the electron from the $n = 2$ orbit to the $n = 1$ orbit are found to be $\lambda_1, \lambda_2, \lambda_3$,and $\lambda_4$ respectively. Then:

• A
  $\lambda_1 = \lambda_2 = 4\lambda_3 = 9\lambda_4$
• B
  $4\lambda_1 = 2\lambda_2 = 2\lambda_3 = \lambda_4$
• C
  $\lambda_1 = 2\lambda_2 = 2\sqrt{2}\lambda_3 = 3\sqrt{2}\lambda_4$
• D
  $\lambda_1 = \lambda_2 = 2\lambda_3 = 3\sqrt{2}\lambda_4$