Question

STACK follows __________ principle, where insertion and deletion is from __________ end/ends only.

• A. LIFO, two
• B. FIFO, two
• C. FIFO, top
• D. LIFO, one

Hint:

Remember: Stack → LIFO (push and pop from top). Queue → FIFO (enqueue at rear, dequeue from front).

Answer 1

The Correct Option is D

Step 1: Understanding stack principle.
A stack is a linear data structure that follows the LIFO (Last In, First Out) principle. This means the element inserted last is the first to be removed.
Step 2: Insertion and deletion operations.
Both insertion (PUSH) and deletion (POP) happen only at one end, called the top of the stack.
Step 3: Eliminate wrong options.
- Option 1: LIFO, two → Wrong, operations occur only at one end.
- Option 2: FIFO, two → Wrong, FIFO describes queues, not stacks.
- Option 3: FIFO, top → Wrong, mixing queue property with stack position.
- Option 4: LIFO, one → Correct, as stack works on LIFO and one-end operation.

Final Answer: \[ \boxed{\text{LIFO, one}} \]