Quiz: Functional Graph Distances

You start at $x$ in a *functional graph* and follow outgoing edges. When is there a path to $y$?

1. A.When $y$ lies on the path you reach by repeatedly following edges from $x$
2. B.Always, because every node has out degree $1$
3. C.Only when $x$ and $y$ are in different cycles
4. D.Only when $y$ has out degree $0$