Which childhood detail suggested Einstein was unusual?

Correct answer: He spoke late and kept to himself

Option A is correct because the biography describes Einstein as a child who began speaking unusually late and often remained quiet and self-contained. These details caused adults to think that he was different from other children, but they did not prove that he lacked intelligence. In fact, the detail introduces his inward-looking nature and suggests that his mind was active even when he did not communicate easily. The other choices are not childhood facts presented in the lesson. Winning every game, becoming an early soldier and giving daily speeches are invented or irrelevant claims. The question therefore checks recall of a specific biographical detail.