A, B and C are three complexes of chromium (III) with empirical formula $$\text{H}_{12}\text{O}_6\text{Cl}_3\text{Cr}$$. All the three complexes have water and chloride ions as ligands. When subjected to heating at $$200^\circ\text{C}$$ the mass of A was found to be constant, while that of B suffered a loss of 6.7%. When 2.66 g of C was treated with $$\text{AgNO}_3$$ it gave 1.43 g of AgCl. The complexes B and C are respectively, chosen from 

1. $$[\text{Cr(H}_2\text{O)}_6\text{Cl}_3]$$, 

2. $$[\text{Cr(H}_2\text{O)}_6]\text{Cl}_3$$,

3. $$[\text{Cr(H}_2\text{O)}_5\text{Cl}]\text{Cl}_2 \cdot \text{H}_2\text{O}$$, 

4. $$[\text{Cr(H}_2\text{O)}_4\text{Cl}_2]\text{Cl} \cdot 2\text{H}_2\text{O}$$ 

5. $$[\text{Cr(H}_2\text{O)}_3\text{Cl}_3] \cdot 3\text{H}_2\text{O}$$