The right option is a. contour interval
The difference in elevation between the highest and lowest contour lines on a topographical map is called contour interval.
A contour interval is the vertical distance between the two contour lines (highest and lowest) in a topographical map. The contour interval is usually stated explicitly on the right-hand lower part in every map. 20 feet for a 1:24,000 map scale is the frequently used contour interval and different contour intervals is available for different maps.
The chromosomes migrate to the equator of the spindle apparatus, they line up in the middle. meta means middle
A demarc is where one network ends and another begins. Demarc stands for demarcation point. It is the physical point at which the public network of a telecommunications company ends and the private network of a customer begins.
However, the distinction between where one category of network begins and another ends is sometimes blurry.
Global Positioning System (GPS)