Which of the following complexes is/are heteroleptic?

(a) CoNH363+

(b) Fe(NH3)4Cl2+

(c) Mn(CN)64-

(d) Co(NH3)4Cl2

Choose the correct option:
1. (a, b)
2. (b, c)
3. (c, d)
4. (b, d)

Heteroleptic coordination complexes that contain more than one type of ligands.

eg, Fe(NH3)4Cl2+ contain NH, and Cl as a ligand is a heteroleptic complex. Similarly, Co(NH3)4Cl2 contain NH3 and Cl as ligand is also a heteroleptic complex

Hence, options (b) and (d) are correct choices.