11. What does the mysteryFunction do if root is the root of a binary tree? int mysteryFunction(struct Node *root) if (rootnullptr) return 0; ) else if (root>leftnullptr && root->rightnullptr) ( return 0; else return 1 + mysteryFunction(root->left) + mysteryFunction(root->right); A. B. C. D. E. F. Returns the number of leaf nodes. Returns the number of internal nodes. Returns the number of nodes in the tree. Returns the height of the tree. Returns the depth of the tree. None of the above