How do you determine whether or not a acid will be destroyed upon the addition dilute bases and acids?

So I have a liter of buffer consisting of .1 M $\ce{HF}$ and 0.05 M $\ce{NaF}$. I'm given three solutions to determine what would essentially destroy the buffer:

(a) 0.050 mol of $\ce{HCl}$
(b) 0.050 mol of $\ce{NaF}$
(c) 0.05 mol $\ce{NaOH}$

Do I assume the aqueous solution of the buffer specifically contain 0.05 M $\ce{F-}$ from the dissociation of the salt. How do I account for the changes in concentration ?

$\ce{HCl}$ would react with nothing but use up some of $\ce{HF}$'s protons, since they have difference in acidities. $\ce{NaF}$ will increase already present concentration. $\ce{NaOH}$ would react with acid $\ce{HF}$. Now a buffer needs to have reasonable amount of both $\ce{HF}$ and $\ce{NaF}$ in almost equal proportions (up to a factor of ten is reasonable). See which is now destroyed.