what does mysteryFunction do here? and why the answer is not (a)&(b)

MC7 (2.5pts) Examine the mysteryFunction below? (Note that in context, t->right will not be NULL.) void mysteryFunction(treeNode * & t) 1 treeNode * y = t->right; t->right = y->left; y->left = t; y->height = max( height (y->right), t->height = max ( height (t->right), t=y; height (y->left)) height(t->left)) 1; 1; + + Which of the following Dictionary functions could invoke mysteryFunction more than once? (a) insert (key); (b) remove (key); (c) find(key) (d) Two or more of these could invoke mysteryFunction more than once (e) None of these would invoke mysteryFunction more than once