Which mixture(s) form(s) buffer solutions? I. 100 mL of 0.200 M HF and 200 mL of 0.200 M NaF II. 200 — Equilibrium Chemistry Question

Which mixture(s) form(s) buffer solutions?
I. 100 mL of 0.200 M HF and 200 mL of 0.200 M NaF
II. 200 mL of 0.200 M HCl and 200 mL of 0.400 M CH₃CO₂Na
III. 300 mL of 0.100 M CH₃CO₂H and 100 mL of 0.300 M CH₃CO₂Na