In order to help the student expand his/her knowledge I will help answer the question. This in hope that the student will get a piece of knowledge that will help him/her through his/her homework or future tests.
Quisling, a Norwegian leader, proved to be an important collaborator for Germany in the invasion of Norway because he provided information to the Germans prior to the invasion and helped them during the attack. The correct answer is letter
d. he provided information to the Germans prior to the invasion and helped them during the attack
I hope it helps, Regards.