Choose the best anwser

1.solar and wid......instead of fossil fuels within 20 years 
A.are used    B.will be used    C.will use     D.will be using 
2.humankind's future..........bright if they can utilize renewable energy in the future
A.is    B.was    C.will be    D.won't be 
3.we...........able to create a future that's free of carbon pollution by using renewale energy sources
A.will be    B.won't be    C.will be being    D.will have been