Explanation:

The Chenab Rail Bridge, an engineering marvel located in the Reasi district of Jammu and Kashmir, India, is the world's highest railway bridge, built over the Chenab River. Therefore, option B is correct. Option A, Dibang, and Option C, Lohit, are major tributaries of the Brahmaputra River, primarily flowing through Arunachal Pradesh, but the world's highest railway bridge is not built over them. Option D, Brahmaputra, is a major river, but the specific record-holding bridge is over its tributary, the Chenab. Thus, A, C, and D are incorrect.