Concept:The contour interval is the vertical difference in height between two adjacent contour lines on a map.Explanation:Look at the map and identify two contour lines that lie next to each other.Note the height value written on the upper contour line and the height value on the lower contour line.Subtract the smaller height from the larger height to find the interval.For example, if the two neighbouring contours are 200m and 250m, the difference is 250m−200m=50m.Therefore, the vertical gap between every consecutive contour line on this map is 50m.Answer:50m — Option A.
