Two protons are moving in different uniform magnetic fields. The magnitude of the field proton I is moving in is twice the magnitude of the field proton II is moving in. If proton I is moving twice as fast as proton II, the radius if the orbit proton II moves around is: O The same size as the orbit of proton I O Half as large as the orbit of proton I O Twice as large as the orbit of proton I O Four time as large as the orbit of proton