The correct answer is B) A rowboat. According to the international and inland navigation rules, a rowboat is required to exhibit a white light from a lantern in sufficient time to prevent collision with other vessels. This is because rowboats are small, low-profile vessels that can be difficult for other vessels to see, especially in poor visibility conditions. Displaying a white light helps make the rowboat more visible to other vessels, reducing the risk of a collision. The other answer choices are incorrect because small fishing vessels, 6-meter motorboats, and 9-meter sailing vessels have different lighting requirements under the navigation rules, which do not necessarily include a white light from a lantern.