Here it says to determine if the vanadium atom is paramagnetic or diamagnetic. So atom means that it's in its neutral form. Vanadium is represented by V. If you look at the periodic table, its atomic number is 23. Here its electron configuration would be Argon 4S23D1.
If we look, we know that in South orbitals there's only one orbital and they can hold a maximum of two electrons. So the 4S orbital is already filled in with two electrons. Our D sublevel has five orbitals. And here there's only one electron there, so vanadium has one electron by itself within an orbital, so it's unpaired, meaning that the vanadium atom is paramagnetic.
So just remember, if you have at least one electron by itself in any given orbital, it's a paramagnetic species.