A colloidal solution is subjected to an electrical field. The particle move towards anode. The coagulation of same sol is studied using `NaCl, BaCl_(2)` and `AlCl_(3)` solutions. Their coagulating power should be
A. `NaCl gt BaCl_(2) gt AlCl_(3)`
B. `BaCl_(2) gt AlCl_(3) gt NaCl_(3)`
C. `AlCl_(3) gt BaCl_(2) gt NaCl`
D. `BaCl_(2) gt NaCl gt AlCl_(3)`