(A): [Ni(CO)4] has a tetrahedral geometry.
(R): CO is a strong field ligand and causes the pairing of electrons in the d-orbitals of Ni.
1
Both A and R are true, and R is the correct explanation of A
2
Both A and R are true, but R is not the correct explanation of A.
3
A is true, but R is false.
4
A is false, but R is true.