Solution
Option 1 -> (A)-(II) doesn't fit grammatically or contextually; tragic accident news doesn't relate to "took for granted."
Option 2 -> (A)-(III) is incorrect; "meandered through" doesn't match the shocking nature of tragic accident news.
Option 3 -> (A)-(IV) "struck me like a thunderbolt" perfectly captures the shocking impact of tragic news; (B)-(III) "meandered through" describes conversation wandering across diverse subjects; (C)-(I) "lesson in life" appropriately completes the orphanage visit experience; (D)-(II) "took for granted" correctly describes Mohan not appreciating his mother's efforts.
Option 4 -> (B)-(I) doesn't work; conversation doesn't "lesson in life" through subjects grammatically.
Hence, Option 3: (A) - (IV), (B) - (III), (C) - (I), (D) - (II) -> Each expression from the passage fits grammatically and contextually: tragic news strikes like thunderbolt (shocking impact), conversation meanders through topics (wandering discussion), orphanage visit becomes a lesson in life (learning experience), and Mohan takes efforts for granted (lack of appreciation) -> correct