If a student performs a titration of 74.0 mL of H₃PO₄ solution of unknown concentration with a standard 1.05 M Ca(OH)₂ solution and requires 26.2 mL of the NaOH solution to reach the third equivalence point, what is the concentration of the H₃PO₄ solution?
A) 0.55 M
B) 0.87 M
C) 0.42 M
D) 1.25 M