Which lines are measured from north to south in relation to the equator?

The correct answer refers to latitude, which is measured from the equator north to south. Latitude lines run parallel to the equator, with the equator itself being at 0 degrees latitude. As one moves away from the equator, latitude increases to 90 degrees at the poles, either north or south. This system helps in determining the position of a point on the Earth's surface in relation to the equator.

Longitude, on the other hand, runs from pole to pole and is measured in degrees east or west of the Prime Meridian, which is located at 0 degrees longitude. Altitude refers to the height of an object above a reference point, usually the Earth's surface, and is not concerned with north or south orientation. The term "Equator Lines" is not a standard term used in geography and does not correspond to a measurement system. Thus, latitude is clearly the correct answer, as it is the system that measures distance north and south from the equator.