Check the Following Paragraphs for Unity

Check the following paragraphs for unity. Then select the letter of the sentence that does not belong in the paragraph.
-(1) All parents want their kids to be safe, happy, and healthy. (2) Therefore, they should make sure that their children learn how to swim. (3) Swimming is fun, and most children enjoy playing in the water once they conquer their fears and improve their swimming skills. (4) Even more important, though, knowing how to swim is a crucial skill that could well save a child's life. (5) When children know how to swim, they are better able to save themselves in the event they fall into a swimming pool or off of a boat. (6) Safety-conscious parents will also make sure that their kids wear bicycle helmets to protect their fragile heads. (7) Finally, kids should know how to swim because it's a great form of exercise. (8) Too many children in our society are overweight, and swimming could be an enjoyable way to help them shed excess pounds.

A) sentence 6
B) sentence 7
C) sentence 8