The correct answer is B) Castellated nut. Castellated nuts are specifically designed to resist loosening due to vibration. They have a series of notches or slots cut around the top edge that allow a cotter pin or locking device to be inserted through the nut and bolt, preventing the nut from working itself loose. This makes castellated nuts the best choice when vibration is a concern, as required for many marine and industrial applications. The other options are not as well-suited for vibration resistance. Square nuts and cap nuts do not have any locking features, while wing nuts are designed for easy hand-tightening and loosening, rather than vibration resistance.