Which of the following is an essential feature of a Doubly Linked List over a Singly Linked List?           

In a doubly linked list, each node contains a reference to both its previous and next node, allowing for efficient traversal in both directions (forward and backward). This contrasts with a singly linked list, which only allows traversal in one direction (forward). The ability to traverse both ways is beneficial in algorithms that require reverse traversals without needing to start from the head again. a) Easier memory management is not specific to a doubly linked list. c) Doubly linked lists use more memory because they store an additional reference to the previous node. d) Direct indexing of elements is a feature of arrays, not linked lists. e) While doubly linked lists do support fast insertion at the head, singly linked lists also offer this feature.