Which Solution Would Have the Greatest Buffering Capacity

Multiple Choice

Which solution would have the greatest buffering capacity?

A) 0.574 M HF and 0.312 M NaF
B) 0.287 M HF and 0.156 M NaF
C) 0.189 M HF and 0.103 M NaF
D) 1.15 M HF and 0.624 M NaF
E) They are all buffer solutions and would all have the same capacity.