Exam SC-400 topic 1 question 67 discussion

Note: Pre-trained classifiers cannot be re-trained

A - reasoning is same as NICKTON81 and techpam

A is correct: Retraining classifiers Retraining published custom classifiers is no longer supported. If you need to improve the accuracy of a trainable classifier you've published, remove the classifier and start over with larger sample sets. To improve the accuracy of an unpublished classifier, review the test results, update the data set with additional data, and restart the training. https://learn.microsoft.com/en-us/purview/trainable-classifiers-learn-about#retraining-classifiers

Retraining published custom classifiers is no longer supported. If you need to improve the accuracy of a trainable classifier you've published, remove the classifier and start over with larger sample sets. https://learn.microsoft.com/en-us/purview/trainable-classifiers-learn-about#retraining-classifiers

Based on I understand from below link, a Custom Trainable Classifier does not need be used in any policy, only publishing is enough to retrain it. So C is seems correct. https://learn.microsoft.com/en-us/purview/trainable-classifiers-learn-about#:~:text=When%20you%20publish%20the%20classifier%2C%20it%20sorts%20through%20items%20in%20locations%20like%20SharePoint%20Online%2C%20Exchange%2C%20and%20OneDrive%2C%20and%20classifies%20the%20content.%20After%20you%20publish%20the%20classifier%2C%20you%20can%20continue%20to%20train%20it%20using%20a%20feedback%20process%20that%20is%20similar%20to%20the%20initial%20training%20process.

I agree based on the answer options, however besides the option I would say only classifier 2 can be retrained: https://learn.microsoft.com/en-us/purview/classifier-how-to-retrain-content-explorer ‘A classifier must already be published and in use before it can be retrained.’