Q: The unit digit of (3 × 1 + 4 × 2 × 1 + 5 × 3 × 2 × 1 + … + 20 × 18 × 17 × ⋯ × 2 × 1) is
(a)2
(b)3
(c)4
(d)5
Correct Answer: (c)
The correct answer is (c): 4. Subject: International Relations | Sub-topic: United Nations Note: This answer was determined through AI-based research. Verify against the official answer key when available.