Geographers most often use this type of map to study the characteristics of regions such as population and natural resources because blank spaces are put into the map to prevent distortion.

azimuthal equidistant
interrupted area
robinson
topographical

Option (2)

Explanation:

Azimuthal equidistant- This type of map is used for the projection in terms of its azimuth.Interrupted area- It is a type of map with equal area and always tries to map accurately without considering the unimportant parts like oceans, thereby leaving them as blank spaces.Robinson- It is a type of map projection used to represent the earth in terms of 2-D map where the scale remains same and is also used for the slope calculation.Topographical- It is a map that shows the topography of an area such as relief, vegetation cover, communication systems, boundaries and so on.  

Thus the correct answer is option (2)

Gravitational force i believe