Athin sphere of a liquid enclosing air or-another gas

If this statement is related to science:

A thin sphere of a liquid enclosing air or-another gas is known as water bubble, soap bubble.

If this statement is not related to science:

The statement is used to refer to a good or fortunate situation that is isolated from reality or unlikely to last.

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.

The answer to this is the 3rd choice!