Which is an example of a three dimensional measurement of
volume?
A. 120 cubic meters
B. 120 grams
C. 120 miles per hour
D. 120 units

The problem here is that according to aufbau principle before 3d orbital 4s subshell comes.after filling 3p orbital with electrons you have 4 electrons left, you place two in 4s with opposite spin and the other two in 3d in any of its two orbitals of total five orbitals with the same spin.