(Finite Automata) Why the following is a NFA?
Here is a similar question:

Which of the following are rational numbers: $$ 1, \frac{2}{3}, \sqrt{2}. $$

The correct answer is that both $1$ and $\frac{2}{3}$ are rationals, despite the fact that $1$ is also an integer.
One thing which is confusing here is that none of the given examples are DFAs or NFAs. Rather, they are pictorial representations of automata. Most of these pictorial representations can be interpreted as NFAs, and some can also be interpreted as DFAs. There would be no ambiguity if the automata were given as tuples, since the transition function of a DFA has signature $Q \times \Sigma \to Q$, whereas the transition function of an NFA has signature $Q \times \Sigma \to 2^Q$.