One mole of which octahedral complex of cobalt will give 2 moles of AgCl as precipitate when reacting with excess silver nitrate solution?
A. [Co(NH₃)₆]Cl₃
B. [Co(en)₃]Cl₃
C. [Co(H₂O)₆]Cl₃
D. [Co(CN)₆]³⁻