The Earth is wrapped in an imaginary reference grid made of two sets of lines:

• Latitudes (parallels) run east–west and measure angular distance north or south of the Equator, from 0° at the Equator to 90° at the poles.
• Longitudes (meridians) run north–south from pole to pole and measure angular distance east or west of the Prime Meridian (0°), up to 180°.

Because any point on the globe can be pinpointed by stating its latitude and longitude values together — a pair of angular measurements — these lines are collectively called geographical coordinates. This is exactly analogous to (x, y) coordinates locating a point on graph paper. Hence the correct answer is Geographical coordinates.

The other terms are not standard geographic vocabulary for this grid: 'geographical boundaries' refer to borders between regions, while 'planetary markers' and 'global divisions' are vague, non-technical phrases that do not describe the latitude–longitude system.