What size volumetric flask would you use to create a 1.00M solution using 166.00 g of KI?

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.

Hope the image of the frequency formula

The answer is b because c don't explain why the moths are on them and it isn't a because as we know only one species of moth does this