Agreen dot in the middle of 4 concentric circles. the first away from the green dot is labeled n = 1. the second circle away from the green dot is labeled n = 2. the third circle away from the green dot is labeled n = 3 and the last is labeled n = 4. there is an arrow from n = 4 to n = 1 labeled a. there is an arrow from n = 3 to n = 2 labeled b. there is an arrow from n = 3 to n = 1 labeled c. there is an arrow from n = 2 to n = 1 labeled d.
which transition by an electron will release the greatest amount of energy?

a
b
c
d