Which of the Following Is True Concerning Lessons Learned on a Project?​

Multiple Choice

Which of the following is true concerning lessons learned on a project?​ 

A)  Lessons learned can only be gathered from project team members. 
B)  Lessons learned are only identified at the end of the project after learning has occurred. 
C)  Lessons learned are the useful knowledge gained by project team members as they perform the project. 
D)  Lessons learned are always provided by the customer.