For coagulation of arsenious sulphide sol, which one of the following salt solutions will be most effective?

For coagulation of arsenious sulphide sol, which one of the following

1.	For coagulation of arsenious sulphide sol, which one of the following salt solutions will be most effective?
A.	BaCl2
B.	AlCl3
C.	Na3PO4
D.	NaCl
Answer» C. Na3PO4