Which of the following decision problems are undecidable? I. Given NFAs…

Which of the following decision problems are undecidable?

I. Given NFAs $N_1$ and $N_2$, is L(N1​) ∩ L(N2​) = ∅ ?

II. Given a CFG $G = (N,Σ,P,S)$ and a string $x ∈ Σ^∗$ , does $x ∈ L(G)$?

III. Given CFGs $G_1$ and $G_2$, is $L(G_1) = L(G_2)$?

IV. Given a TM $M$, is $L(M) = Φ$?