GMAT Sentence Correction (SC) | Re: The only way for a team to win the $10 million Ansari X

The only way for a team to win the $10 million Ansari X Prize for private manned spaceflight isfor them to privately finance and successfully launch a reusable craft on a 62-mile-high flight twice within two weeks with a live human pilot on board.

A.for them to privately finance and successfully launch a reusable craft
B.if they privately finance and successfully launch a reusable craft
C.if a reusable craft is privately financed and successfully launched by them
D.by privately financing