Concept:Latitudes are imaginary circles parallel to the Equator. The Equator is the largest circle of latitude, located at 0°.Explanation:The Earth is spherical. Latitudes shrink as they move away from the Equator. The Equator has the greatest circumference (about 40,075 km). Other latitudes like the Tropic of Cancer (23.5°N), Tropic of Capricorn (23.5°S), and Arctic Circle (66.5°N) are smaller circles. Thus, the Equator is the longest latitude.Answer:A. Equator