A max-heap is a heap where the value of each parent is greater than or equal to the value of its children. Which of the following is a max-heap?
In option (A) - it is not a max heap because it is not a Complete Binary Tree (a heap must have all levels till last but one completely filled and in the last level all nodes must be filled from the left end without a gap till the last node)
In option (C) - it is complete binary tree but is not following the max heap property i.e. the value of parent node is not always greater than the child nodes as the node of value $5$ is less then one of its child node value of $8.$
In option (D) - similar to (C) option explanation here node of value $2$ is less than the child node value $4.$
Correct option is (B) and it satisfies all the properties of a max heap.
in option (A) - it is not a max heap because it is not complete binary tree
@ASHU2015 correct this line
it is not a max heap because it is not Almost Complete Binary tree. Because Heap Must Be Complete binary tree or almost complete binary tree.