If three electrons are available to fill five empty 3d atomic orbitals, how will the electrons be distributed in the five orbitals?

Answer is: one electron in the first three orbitals, none in the fourth or fifth orbitals.  All three electrons will have parallel spins (unpaired electrons).
This is Hund's rule - orbitals of the same energy are each filled with one electron before filling any with a second, these first electrons have the same spin. 

The correct answer would be b) volume versus temperature, because they are also directly proportional.

I'm sorry i cant you if you don't list the elements : (