the surface layer of the land measured from the ground level down to the point of change is the ?

Maybe a horizontal because its a pattern

Historians are researchers of the past or people who understand the history of people. with this field, they must possess qualities such as being unbiased, patient, efficient reader, has a knack for logic and critical thinking and reasoning, disciplined, open-minded, resourceful, with good analytical ability, good reasoning skills and problem solving!

Add the map and the options so i can further you, you so much. : )