Which data structure is best described by offering fast insertion at the head and linear-time access by position?

• A. Array
• B. Linked List
• C. Hash Table
• D. Queue

Answer: (B)

Time-performance trade-offs for data structures when inserting at the front and accessing by index are being tested. In a linked list, adding a new node at the front is done by creating the node and re-pointing the head to it, which is a constant-time operation. But to reach a specific position, you start at the head and follow the next pointers step by step until you arrive at that index, which takes linear time. So this structure delivers fast insertion at the head and linear-time access by position, matching the description. An array, by contrast, allows quick access by position but inserting at the head requires shifting every element, giving an O(n) cost. A hash table is indexed by keys, not by position, so access by position isn’t meaningful here. A queue emphasizes end-based operations and does not provide efficient random access by position.