Since Rachel has been leaning forward throughout the evening, Rachel, I believe was being lustful to Matthew in a seductive way and in human first impression Matthew leaned back in his chair. but don't take my word for it.
The first would be A. Adding ellipses after "One day" isn't right, and A is the only one that doesn't do that.
The second is The first game (to be held in the new gym) is against Rocky Point High School. "To be held in the new gym" gives clarification about "the first game."
The third is The new inductee proclaimed, "It (my membership) is my greatest honor!"
"My membership" provides more info on what "it" is.