Read the passage and answer the question.For most of human history, boredom was simply part of life. People waited for crops to ripen, for letters to arrive, for the rain to stop. Today, a phone in the pocket promises that no moment need ever be empt…

Read the passage and answer the question.

For most of human history, boredom was simply part of life. People waited for crops to ripen, for letters to arrive, for the rain to stop. Today, a phone in the pocket promises that no moment need ever be empty. Yet psychologists increasingly argue that this constant escape comes at a cost. When the mind is left without an outside task, it does not switch off; instead, it begins to wander, joining memories, plans and stray ideas in unexpected ways. In several studies, people who first completed a dull task, such as copying numbers from a list, later gave more original answers in a creativity test than those who went straight to it.

This does not mean that all boredom is useful. Chronic boredom, the kind felt by someone trapped in work that never changes, is linked to poor health and risky behaviour. The difference lies in what we do with the feeling. Brief, ordinary boredom acts like a signal, telling us that our present activity no longer satisfies us and nudging us towards something more meaningful. If we silence that signal the instant it appears, we may never hear what it is trying to say.

The practical advice, then, is modest. Leave the phone behind on a short walk. Let a child stare out of the window on a long journey. Such small gaps, far from being wasted time, may be where some of our best thinking quietly begins.

Which of the following best states the main idea of the passage?

A. Phones should be banned for children.

B. Boredom of every kind is harmful to health.

C. People in the past were more creative than people today.

D. Short, ordinary spells of boredom can help thinking, though long-lasting boredom is harmful.