Which one of the following ions exhibits d-d transition and paramagnetism as well?

Match the metal ions given in Column I with the spin magnetic moments of the ions given in Column II and assign the correct code :

Column - I	Column - II
A. Co3+	(i) $$\sqrt 8 $$ B.M.
B. Cr3+	(ii) $$\sqrt {35} $$ B.M.
C. Fe3+	(iii) $$\sqrt 3 $$ B.M.
D. Ni2+	(iv) $$\sqrt {24} $$ B.M.
	(v) $$\sqrt {15} $$ B.M.

The geometry and magnetic behaviour of the complex [Ni(CO)₄] are

The type of isomerism shown by the complex [CoCl₂(en)₂] is