What does a flatter slope indicate about the spacing of contour lines?

Answer: B — The lines are farther apart.

A flatter slope on a contour map indicates that the contour lines are spaced farther apart. This occurs because contour lines represent points of equal elevation; when the terrain is relatively flat, there is less change in elevation over horizontal distances. Consequently, the distance between successive contour lines increases, reflecting a gentler gradient. Conversely, when there is a steep slope, the elevation changes rapidly over short distances, which leads to contour lines being closer together. Therefore, the relationship between the slope's steepness and the spacing of contour lines is key to interpreting topography effectively.