The Crimean War occurred in Europe, and did not involve China, ruling out A. The Nationalist Revolution was between the Nationalists and the Qing government, ruling out C. The Opium War was about Chinese trade, but wasn't necessarily a revolt against Europe, bc China was still independent, and didn't involve a secret society, ruling out D. The Boxer Rebellion, however, was an anti-European and anti-foreign revolt that did involve a secret society known as the Yihetuan, meaning B is correct.
