Determining which states in a transition system satisfy a specific CTL formula
A hint that might put you in the right direction:
Note that $\exists Xc$ (where $X$ is the "next" operator) holds in every state from which there exists a neighbor with $c$. Thus, for example, $1\models \exists Xc$.

Now, $\forall (\phi U \psi)$ holds if in all computations $\phi$ holds until $\psi$ holds. In particular, every state that satisfies $\psi$ also satisfies $\forall (\phi U \psi)$, since the eventuality holds immediately.

Thus, $1$ satisfies the formula. See if you can complete the rest of them now.