This Hello can be summarized as
1. Go To Left
2. Increment counter "WhichNode". This is static variable , so it will retain values to calls. This will contain When this node will be printed in Inorder Traversal.
3. Go to Right.
It is Left Node Right Traversal & This code would have correctly calculated option A have there not been error in step 3, second call to hello. Hello(t->right, n,p) -> here p is undefined, so correct answer is E. None of the above. (Option which is not given !)