6-76

d is not correct

e is the correct answer because the following orbitals are NOT arranged in order of increasing energy:

e) 6s < 5f < 6p

The other four answers are arranged in order of increasing energy:

a) 3s < 4s < 5s

b) 5s < 5p < 5d

c) 5s < 4d < 5p

d) 6s < 4f < 5d