Quiz: Node Capacity Modeling

A problem has node capacity limits where each node handles at most $c$ units. How do you model this in a standard flow network?

1. A.Set all outgoing edge capacities to $c$
2. B.Reduce all incoming edge capacities to $\min(\text{capacity}, c)$
3. C.Add a self-loop of capacity $c$ to each node
4. D.Split each node into $v_{in}$ and $v_{out}$ connected by an edge of capacity $c$