Retrieval operation is fastest in which data structure a) Heapb) Stack c) Linked list d) None

The retrieval operation is fastest in a Stack data structure.

Here's why:

a) Heap: A heap is a complete binary tree and is particularly useful in algorithms involving sorting and priority queues. However, retrieval operations are not the fastest in a heap because elements are not stored in a specific order that allows for fast retrieval.

b) Stack: A stack follows the Last-In-First-Out (LIFO) principle. This means that the last element inserted is the first one to be retrieved, which makes retrieval operations very fast. In fact, it takes constant O(1) time complexity.

c) Linked list: In a linked list, elements are linked using pointers. Retrieval operations in a linked list are not the fastest because you have to traverse the list from the head to get to an element, which can take linear O(n) time in the worst case.

d) None: This is not a data structure.

So, the answer is b) Stack.