The Figure Shows Part of the Energy Level Diagram of a Certain

Multiple Choice

The figure shows part of the energy level diagram of a certain atom. The energy spacing between levels 1 and 2 is twice that between 2 and 3 . If an electron makes a transition from level 3 to level 2 , the radiation of wavelength $\lambda$ is emitted. What possible radiation wavelengths might be produced by other transitions between the three energy levels?

A) only $\lambda / 2$
B) both $\lambda / 2$ and $\lambda / 3$
C) only $2 \lambda$
D) both $2 \lambda$ and $3 \lambda$