D obviously, the title also explains a lot of "the failure of the Boxer Rebellion led to the full exposure of the flattering and abusing behavior of the Qing court, which fundamentally changed the attitude of Chinese people towards the Qing court, and more people embarked on the revolutionary road against the Qing dynasty."

B, this sentence is the harm of humiliating treaties. It was only after the treaties and contents signed by the Qing government and the eight countries that this sentence was drawn. It was not derived from the failure of the Boxer Rebellion, so B ruled it out.