The correct answer is A) change altitude rapidly. When taking stars for navigation, the bodies to the east and west will change altitude rapidly compared to those to the north and south. This is because the stars to the east and west are moving across the plane of the horizon, while the stars to the north and south appear to be moving in the plane of the horizon. As the Earth rotates, the eastern and western stars will rise and set more quickly, resulting in a rapid change in their observed altitude. The other options are incorrect because B) the stars do not remain in a fixed position, C) the change in altitude is rapid, not slow, and D) the stars to the east and west are not moving in the plane of the horizon.