Word Choice and Sentence Meaning
Thank you for your time!
I am encountering an problem and having different opinion with my friend.
1. What is rational for each person acting unilaterally might not be best ( ) all to act in concert.
A. for B. if C. were D. When
I think the answer should be when, which means what is best for one person while acting is not the best for everyone when they play together. However, my friend thinks it should be for, be best for all, means good to everyone. I think i am right but i cant persuade him since I am not a native speaker.
Can someone help me with it? Thank you very much!