When trending megohmmeter readings on a shipboard motor over successive maintenance periods, a technician observes that each successive reading, taken under similar temperature and moisture conditions, is lower than the previous one. Which conclusion is best supported by this trend, and what additional precaution applies when interpreting the data?

1. A. The insulation is improving; lower megohm values indicate reduced leakage paths and the trend requires no corrective action
2. ✓ The insulation is degrading; however, because readings are strongly affected by temperature and moisture, values must be corrected and trended over time rather than judged against a single pass/fail numberCorrect
3. C. The motor windings have an open circuit; the megger should be replaced with a standard ohmmeter to confirm continuity
4. D. The readings indicate normal variation; megger values are not reliable for trending and should only be used for single-point pass/fail determinations