Java instantiated and initialized list (Explanation needed)-CodePudding

Could someone help me understand why the answer to this is (B)?

private List<String> animals;
public void manipulate()
{
    for (int k = animals.size() - 1; k > 0; k--)
    {
      if (animals.get(k).substring(0, 1).equals("b"))
      {
        animals.add(animals.size() - k, animals.remove(k));
        }
    }
}

Assume that animals has been instantiated and initialized with the following contents. ["bear", "zebra", "bass", "cat", "koala", "baboon"] What will the contents of animals be as a result of calling manipulate ?

(A) ["baboon", "zebra", "bass", "cat", "bear", "koala"]
(B) ["bear", "zebra", "bass", "cat", "koala", "baboon"]
(C) ["baboon", "bear", "zebra", "bass", "cat", "koala"]
(D) ["bear", "baboon", "zebra", "bass", "cat", "koala"]
(E) ["zebra", "cat", "koala", "baboon", "bass", "bear"]

CodePudding user response：

on first iteration,

K=5  
Baboon is added to index (6 - 5), you get (D)

second iteration,

K=4, element is cat
nothing happens.

third iteration,

K=3, element is bass
bass is added to index (6-3), gets added to its own index, remains (D)

fourth iteration,

K=2, element is zebra
nothing happens.

fifth iteration,

K=1, element is baboon
baboon is added to index (6-1) which is its original index, you get (B)

sixth iteration,

K=0. there is no iteration as condition k>0 is not fulfilled.