Final answer:
The best method to measure learning after a 4-week series on achieving customer satisfaction is a Pre/Post-test.
Step-by-step explanation:
To measure if and what learning has actually taken place after the 4-week series on achieving customer satisfaction, the best method would be a Pre/Post-test. This method involves administering a test to participants before and after the training program to assess their knowledge and understanding of the subject. By comparing the scores, you can determine if learning has occurred and to what extent.