Quiz: Dijkstra Optimization

In Dijkstra, you pop node $v$ with distance $d$ from the queue. You've already processed $v$ with distance $d' < d$. What should you do?

1. A.Skip this entry (continue to next)
2. B.Update the distance to $(d + d')/2$
3. C.Process $v$ again with the new distance
4. D.Restart Dijkstra from $v$