1. Which sentence is punctuated correctly? I think that (Christina and I) will be counselors at the camp when we're older. Christina and I went to the same summer camp for years (since we were 8). I preferred to (ride horses) and spend time playing different outdoor sports. Christina spent time in the arts (and crafts cabin), making things to send home.

B is correct, " Christina and I went to the same summer camp for years (since we were 8) " parentheses are used when you have some extra information you want to add, but its not completely necessary. Like how they started going to the same summer camp when they were 8, you can still read the sentence fine without it, but it's a nice piece of information.