The Titration of 80

Multiple Choice

The titration of 80.0 mL of an unknown concentration H₃PO₄ solution requires 126 mL of 0.218 mol L^-1 KOH solution. What is the concentration of the H₃PO₄ solution (in mol L^-1) ?

A) 1.03 mol L^-1
B) 0.343 mol L^-1
C) 0.114 mol L^-1
D) 0.138 mol L^-1
E) 0.0461 mol L^-1