Step Node Chosen Neighbor g(n) h(n) f(n)
1 A B 2 4 6
    C 4 2 6
2 B C 5 2 7 (ignored)
    D 7 0 7
3 C D 5 0 5 (update)
4 D – – – –
  1. B
  2. B
  3. B
  4. B