Solution

We are asked to match the algorithms/applications with the data structures they commonly use.

Step 1: Analyze Each Pair

• BFS (Breadth-First Search): Uses a queue to keep track of nodes at the current level. → Matches with (IV) B Queue.
• DFS (Depth-First Search): Uses a stack (explicit or call stack) to explore nodes deeply. → Matches with (I) Stack.
• Heap Sort: Requires a priority queue or heap data structure for efficient sorting. → Matches with (III) Priority Queue.
• Storage on secondary storage devices: Often implemented using B-trees for indexing. → Matches with (II) B Tree.

Step 2: Match List-I with List-II

(A)-(IV), (B)-(I), (C)-(III), (D)-(II)

Answer: Option A