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 A — the dielectric-absorption effect of the insulation

Dielectric absorption is the gradual alignment of molecular dipoles within insulating materials under a strong electric field. This polarization process requires time, continuously drawing charging current and causing the megohmmeter resistance pointer to rise steadily during prolonged cranking.