GATE Computer Science (CS) 2019 Solved Papers

Consider the following statements:
I. The smallest element in a max-heap is always at a leaf node
II. The second largest element in a maxheap is always a child of the root node
III. A max-heap can be constructed from a binary search tree in $\mathit{\Theta }\left(\mathit{n}\right)$ time
IV. A binary search tree can be constructed from a max-heap in $\mathit{\Theta }\left(\mathit{n}\right)$ time
Which of the above statements are TRUE?