[单选题]
According to the selecti2 s xth ycx 80d )ove26rorb(sd5rj06von rule, wdf8n38b,f1mluuy68luh fq 4l hen a photon is emitted or absorbed, transitions can only occur between stateu8fflfm dn8 41bqu,6l 3uyl 8h with values of l that differ by
A. four units.
B. three units.
C. two units.
D. one unit.
Post time 2024-1-22 00:52:27