5. The man's problem is that he does not know how students felt about the field trip because students did not participate in giving sincere opinions about it.
The woman and the man suggest two possible solutions to the problem. The first suggestion is to arrange a discussion during class. The second suggestion is to simplify the previous feedback form by changing the questions to multiple choice into multiply choice.
I think that second suggestion is better for him. This is because if he tries to receive feedback during class, everyone will hesitate to present their truthful reviews of the field trip. Also, even though multiple-choice form questions have has some limitations for getting detailed reviews, he can still receive significant information like negative opinions that he wants.
For these reasons, I would recommend the second suggestion for him.
comments: 혹시 리스닝에 어떤 field trip이였는지에 대해서도 나왔었나요? 첫 문장이 조금 abrupt하게 느껴집니다. 왜 남자가 field trip 관련 피드백을 받아야하는 상황인지에 대한 설명이 나왔었다면 (예를 들어 field trip organizer였다던가..) 그런 부분들을 스피킹에 넣어주시면 좋을 것 같습니다. 제시하신 이유는 모두 적절하고 이유에 대한 설명도 잘 되어있습니다.