Answer:
D. They realize that he is the only person who is willing to participate
Explanation: Because he has a lot of determination.
Charlie is chosen for the experiment because he is a hard worker who desperately wants to learn, despite the many setbacks and limitations he encounters. The researchers know this because Ms. Kinnian vouches for him.
B. why our city needs more carpool lanes, because that topic doesn't have much evidence/facts/info to back it up as the other ones.
The only conjunction in this sentence is C) but.
All of the other options are prepositions, not conjunctions.
The second one, and the last one
C should be the correct answer
