Which of the Following Yields a Buffer Solution When Equal

Multiple Choice

Which of the following yields a buffer solution when equal volumes of the two solutions are mixed

A) 0.050 M H₃PO₄ and 0.050M HCl
B) 0.050M H₃PO₄ and 0.025 M HCl
C) 0.050M NaH₂PO₄ and 0.025M NaOH
D) 0.050M Na₃PO₄ and 0.050M M NaOH
E) 0.050M Na₃PO₄ and 0.025M NaOH