Which is the best topic sentence for a paragraph within a paper

More and more people are quitting smoking because it increases the risk of lung cancer.

When someone decides to quit smoking the risk for lung cancer and many other types of cancer is reduced. You reduce the risk for heart disease, stroke, and peripheral vascular disease (narrowing of the blood vessels outside your heart within 1 to 2 years of quitting.

Explanation:

"get off of your lazy bum and come running with me or i'm dumping this pitcher of water on u " u say with a smile. she thinks your joking so she ignores you about 10 seconds later shes screaming wile water is dripping everywhere you say "here comes the second one! " then you here her say okay, your such a j e r k ! ill be ready in 5 put the pitcher down " she say in an angry tone. and you smile in victory

good enough?