Select each choice that is a proof method for showing that a language L is context free.

a$)$ Show that there is an epsilon$-$NFA that accepts L

b$)$ Show that L is the intersection of two context free languages

c$)$ Show that there is a PDA accepting by empty stack that accepts the complement of L

d$)$ Show that L$=$K$*$ for a language K accepted by a PDA accepting by final state