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) 0.10 M NH₃ and 0.10 M HCl
B) 0.10 M NH₄⁺ and 0.10 M KOH
C) 0.20 M NH₃ 0.10 M KOH
D) 0.20 M NH₃ and 0.10 M HCl
E) 0.20 M NH₄⁺ and 0.10M HCl