The five items: A, B, C, D, and E are pushed in a stack... popped four times... inserted in queue... two deleted from queue... pushed back on stack... one popped. The popped item is
- A. A
- B. B
- C. C
- D. D
Answer: D. D
Explanation: Stack: [ABCDE]. Pop 4: E,D,C,B. Queue: E,D,C,B. Delete 2: E, D. Stack: [A, E, D]. Pop 1: D.