Which of the following cannot be explained by crystal field theory?

Which of the following are true about the energy of the given d-orbitals of a tetrahedral complex?
$A$. $d_{xy} = d_{xz} > d_{x^2-y^2}$
$B$. $d_{xy} = d_{yz} > d_{z^2}$
$C$. $d_{x^2-y^2} > d_{z^2} > d_{xz}$
$D$. $d_{x^2-y^2} = d_{z^2}$
Choose the correct answer from the given below:

$[Fe(CN)_{6}]^{4-}$ and $[Fe(H_{2}O)_{6}]^{2+}$ are of different colours in dilute solutions. Why?

For a $d^{4}$ metal ion in an octahedral field,the correct electronic configuration is:

Draw a figure to show the splitting of $d$ orbitals in an octahedral crystal field.

The increasing order of field strength of ligands is: