Which lines run east and west and are used to measure degrees of latitude?

Parallels are the lines that run east and west on a globe, and they are used to measure degrees of latitude. Latitude refers to the geographic coordinate that specifies the north-south position of a point on the Earth's surface. Each parallel is a circle around the Earth that is parallel to the equator, and they are typically measured in degrees from the equator, which is designated as 0 degrees latitude, extending to the poles at 90 degrees north and south.

In contrast, meridians are the lines that run north and south and measure degrees of longitude, which is a different geographic coordinate. Longitude measures how far east or west a point is from the Prime Meridian. Thus, parallels are specifically associated with latitude, making them the correct choice in this context.