The answer is B. "The man who had a joyful marriage had children who caused him no end of worry." (paragraph 8)
How to explain
Although the other options provide context and details about the situation, option B directly addresses the messengers' struggle.
It highlights the universal nature of problems and challenges, suggesting that everyone, even those who appear fortunate, have their own difficulties.
This realization could have disheartened the messengers, as they encountered people with seemingly perfect lives yet still burdened by worries. It emphasizes the difficulty of their task, searching for a cure in a world where even basic happiness is elusive.
The Complete Question
The King's Ailment
(Paragraph 8) The king was a troubled man. His health had been failing for some time, and no physician could find the cause. In desperation, he sent out messengers throughout the kingdom, from one end to the other and from side to side, searching for someone who could cure him. They traveled for weeks, enduring harsh weather and treacherous terrain, but found no one who could offer a solution. The man who had a joyful marriage had children who caused him no end of worry. Everyone could complain about something. It seemed that even the most fortunate people were plagued by their own problems.
(Paragraph 9) Over many days, the king's health did not change. He grew weaker and weaker, and his advisors began to fear the worst. The messengers, exhausted and disheartened, returned to the palace, empty-handed. They told the king of their journey, of the many people they had met and the stories they had heard. But none of them brought any news of a cure.