I personally think it's C I hope it's right if not I'm Sorry
Total 52 students.
52 - 17 = 35 students left
35 - 5 = 30 students left
30 - 2 = 28 students left
Each class has 11 students that play ONE sport, which means 22 total in 2 classes. You're on your own now! It's not that hard, I'm sure you'll figure it out.
Answer:
The third one. The square in the top left can only fold to the right or down.... which means there is guaranteed to be an open side remaining on the square.