Which One of the Following Aqueous Solutions, When Mixed with an Equal

Which one of the following aqueous solutions, when mixed with an equal volume of 0.10 mol L⁻¹ aqueous NH₃, will produce a buffer solution?

A) 0.10 mol L ⁻¹ HCl
B) 0.20 mol L ⁻¹ HCl
C) 0.10 mol L ⁻¹ CH ₃COOH
D) 0.050 mol L ⁻¹ NaOH
E) 0.20 mol L ⁻¹ NH ₄Cl