Question

knowing how to read a city map is a valuable skill. first, figure out your location on the map. check the street signs at the nearest intersection and use clues to help you find that intersection on the map. for example, if you are near a bridge or a park, look for those symbols on the map. the maps legend indicates what the symbols mean.
a maps compass rose reveals where north is. to establish direction, walk a block and revisit your map; compare where you were to where you are. in which direction did you travel? then locate your destination on the map.
the maps scale indicates distance ratios; for example, an inch may be equal to five hundred feet. now you know where you are, how to get where you are going, and how far you have to go!
which best shows that the authors purpose is to explain to readers how to navigate a city with a map?
the author states a clear position (a maps compass rose reveals where north is) and provides reasons to support it.
the author outlines steps to follow, such as figure out your location and establish direction.

Explanation:

The text provides a series of steps like "figure out your location", "establish direction", etc. which are typical of an instructional text on how to do something (navigate with a map). The first option about stating a position and reasons is more of an argumentative structure, not instructional.

Answer:

The author outlines steps to follow, such as figure out your location and establish direction.