What is the rule for accurately reading grid coordinates on a map?

The correct answer involves the principle of accurately interpreting grid coordinates on a map, which is fundamental in navigation and map reading. Grid coordinates help identify specific locations on a map that is divided into a grid pattern.

When reading grid coordinates, the convention is to first determine the east-west position, followed by the north-south position. This means you start by moving horizontally across the grid from left to right to find the east-west reference, which provides the column number. After establishing this, you then move vertically from the bottom to the top of the grid to find the north-south reference, yielding the row number.

This left-to-right for the horizontal (east-west) measurement and bottom-to-top for the vertical (north-south) measurement embodies the correct approach to reading grid coordinates. The principle highlighted in the correct answer reflects the standard practice for accurate map reading.