When a megohmmeter is used to test insulation, what condition causes the gradual rise of the pointer reading as a result of continued cranking?

Correct Answer: Option B — the dielectric-absorption effect of the insulation

The gradual pointer rise during a megohmmeter test stems from the dielectric-absorption effect, where electrical energy is absorbed by the insulation material. As polarizing and charging currents gradually decrease over time, the apparent insulation resistance reading increases continuously during the cranking cycle.