Assertion : According to crystal field theory , during complex formation , the d-orbitals split and form two sets of orbitals `t_(2g)` and `e_(g)` .
Reason : Splitting of d-orbitals occurs only in case of strong field ligands .
A. If both Assertion and reason are true and reason is the correct explanation of assertion
B. If both assertion and reason are true but reason is not the correct explanation of assertion
C. If assertion is true but reason is false
D. if both assertion and reason are false