What do radio waves and microwaves have in common? O Both have shorter wavelengths than visible light
O Both are at the side of the spectrum that has the highest frequency
O Both have lower frequencies than visible light
O Both have radiant energy than visible light.

The correct answer is c

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.