Question 1902Navigation General

The correct answer is C) 90°. The distance in longitude from the intersection of a great circle and the equator to the lower vertex is 90° of longitude. This is because a great circle, such as the equator, intersects the equator at a right angle (90°). Therefore, the distance in longitude from the intersection to the lower vertex, which is also on the equator, is 90° of longitude. The other options are incorrect because 45° is not the correct distance, 135° is more than 90°, and 180° is the maximum distance, which is not the case here.