People donated a lot, so the victims of the tsunami are now able to overcome difficulties.      

A But for people's generous donation, the victims of the tsunami wouldn't be able to overcome difficulties now.

B Despite people's generous donation, the victims of the tsunami are facing lots of difficulties now.

C To overcome difficulties, the victims of the tsunami needed people's generous donation.

D The victims of the tsunami are now able to overcome difficulties but for people's generous donation.