Which statement about parallels of latitude is true?

• A. They are great circles that pass through the poles.
• B. They are circles on the Earth's surface that pass through the center.
• C. They are small circles on the Earth’s surface that do not pass through the center (except the equator).
• D. They are lines that cross every meridian.

Answer: (C)

Parallels of latitude are circles on the Earth’s surface that lie in planes parallel to the equatorial plane. Because of this, their centers are offset from the Earth’s center, so they are smaller than the Earth’s equatorial great circle. The equator is the exception: its plane does pass through the Earth’s center, so it is a great circle.

So the true statement is that parallels are small circles on the Earth’s surface that do not pass through the center (except the equator). The other ideas describe different features: great circles through the poles refer to meridians, and lines that cross every meridian describe lines of longitude, not latitude.