Of the measurement examples given, which would you say was the most accurate measure of training success? Why?

Technological innovation and stiff competition drive constant change in the telecommunications industry.
Therefore, Verizon needs to train its sales and customer service employees frequently to familiarize them with the latest products, services, and pricing arrangements. Verizon is committed to measuring training outcomes and applying the analysis to future efforts. Consider how the company evaluated three recent training programs.
When rolling out a new pnc1ng plan, Verizon needed swift training just before the new plan launched, in order to keep the plan details confidential as long as possible. Over six days, the company provided its sales and customer service employees with lectures, digital learning, and roleplaying.
The need to move quickly and train all employees at once made the pre-test/post-test approach impractical.
In surveys, employees and their managers reported higher confidence and sense of feeling prepared than with previous pricing launches.
In addition, the company had earlier taught customer service employees skills for handling calls more effectively.
The company then determined that the employees were handling calls faster and with better outcomes after the training than beforehand.