What Is the Molarity of a Potassium Triiodide Solution,KI₃(aq),if 30

Multiple Choice

What is the molarity of a potassium triiodide solution,KI₃(aq) ,if 30.00 mL of the solution is required to completely react with 25.00 mL of a 0.200 M thiosulfate solution,Na₂S₂O₃(aq) ? The chemical equation for the reaction is:
2 S₂O₃^2-(aq) + I₃^-(aq) → S₄O₆^2-(aq) + 3 I^-(aq)

A) 0) 0833 M
B) 0) 120 M
C) 0) 167 M
D) 0) 333 M