The intersections of parallels are truly spaced along which geographic reference line?

• A. Equator
• B. Prime Meridian
• C. Tropic of Cancer
• D. Antarctic Circle

Answer: (A)

Parallels are circles of latitude that run east-west and stay parallel to the equator. The spacing between these parallels is described by differences in latitude, which are defined as angular distances from the equator. Because latitude is anchored to the equator as the baseline, the true spacing of successive parallels is measured with respect to that equatorial reference. In other words, the equator provides the natural baseline for how far apart parallels are, in angular terms, and the corresponding surface distance is the same per degree of latitude along any meridian.

The other options don’t fit as the reference for spacing of all parallels. The Prime Meridian sets zero longitude, not the spacing of latitude lines. The Tropic of Cancer and the Antarctic Circle are specific parallels, not the reference for general spacing.