A close in leveling is defined as what?

• A. The sum of all rises.
• B. The difference between the starting level of the initial point for the outward run and the end of the return run.
• C. The difference between the first and last observations.
• D. The sum of all foresights.

Answer: (B)

In close-in leveling, you run a level line outward from a starting point and then return along the same line to close the loop. The close-in is the residual vertical difference between the starting elevation and the final elevation after completing the return. This difference shows how accurately the level line closed; ideally it should be zero, and in practice you compare it to tolerances and use it to judge data quality or repeat measurements.

This option describes that specific difference: the starting level of the initial point for the outward run versus the end of the return run. The other ideas—sum of rises, the difference between the first and last observations, or the sum of foresights—refer to different calculations and do not define the close-in.