Final answer:
David is concerned about group unity.
Step-by-step explanation:
The student is concerned about Group unity as mentioned in the passage. The narrator expresses that there was a feeling of unity among the group, which is what David was concerned about.
David wonders if he is overthinking and making a big deal out of nothing. He is unsure if the wave they are facing is the right thing. So, the answer is option 2) Group unity.