Yuo need to do lots of exercise ____ health.A.stay B.staying

Yuo need to do lots of exercise ____ health.A.stay B.staying C.for stay D.to stay
By the way:
1-You can run,swim ____play basketball.
A.and B.then C.or D.but
2-Change your diet and lifestyle ____ today.
A.for B.on C.from D.after
3-You can always feel young __ the right food and right exercise.
A.and B.without C.because D.with