Which mixture of solutions can be used to prepare a buffer solution?

A.     ${\text{50.0 c}}{{\text{m}}^{\text{3}}}{\text{ 0.100 mol}}\,{\text{d}}{{\text{m}}^{ - 3}}{\text{ HCl}}$ and ${\text{100.0 c}}{{\text{m}}^{\text{3}}}{\text{ 0.100 mol}}\,{\text{d}}{{\text{m}}^{ - 3}}{\text{ N}}{{\text{H}}_{\text{3}}}$

B.     ${\text{50.0 c}}{{\text{m}}^{\text{3}}}{\text{ 0.100 mol}}\,{\text{d}}{{\text{m}}^{ - 3}}{\text{ HCl}}$ and ${\text{50.0 c}}{{\text{m}}^{\text{3}}}{\text{ 0.100 mol}}\,{\text{d}}{{\text{m}}^{ - 3}}{\text{ N}}{{\text{H}}_{\text{3}}}$

C.     ${\text{50.0 c}}{{\text{m}}^{\text{3}}}{\text{ 0.100 mol}}\,{\text{d}}{{\text{m}}^{ - 3}}{\text{ HCl}}$ and ${\text{100.0 c}}{{\text{m}}^{\text{3}}}{\text{ 0.100 mol}}\,{\text{d}}{{\text{m}}^{ - 3}}{\text{ N}}{{\text{H}}_{\text{4}}}{\text{Cl}}$

D.     ${\text{50.0 c}}{{\text{m}}^{\text{3}}}{\text{ 0.100 mol}}\,{\text{d}}{{\text{m}}^{ - 3}}{\text{ HCl}}$ and ${\text{50.0 c}}{{\text{m}}^{\text{3}}}{\text{ 0.100 mol}}\,{\text{d}}{{\text{m}}^{ - 3}}{\text{ N}}{{\text{H}}_{\text{4}}}{\text{Cl}}$

A