Well the only thing that comes to mind for me, is when I was younger and we had to do a science fair project. We did a solar system, and it was four of us partnered together. We each collaberated and took different parts. I was the one who had to find materiel for the solar system. The others did the colors, and how they were going to make it move around and rotate.
I agree, the answer is a. The colon after attitude helps separate the cause and the explanation. All the other answers don't make sense because they didn't separate it properly.
