Where in a max-heap might the smallest element reside, assuming that all elements are distinct?

The smallest element may only reside in a leaf node. By the max heap property, any node that is a parent holds a value that is greater than another node’s value (its children) and so cannot be the smallest value. Therefore our smallest value node must not be the parent to another node. Beyond this, however, there is no distinction of which leaf node holds the smallest value and so it could be any of them.