According to 21 CFR 211.192, what is required when any unexplained discrepancy or failure of a batch to meet specifications is found?

Choices

1. A. The batch should be immediately destroyed
2. B. A thorough investigation should be made, extending to other batches that may have been associated with the specific failure or discrepancy
3. C. Only the affected batch needs to be quarantined; no investigation is needed
4. D. The discrepancy can be noted in the batch record without further action