CR Time Consuming but intelligent

It may someday be worthwhile to try to recover uranium from seawater, but at present this process is prohibitively expensive.

(A) It may someday be worthwhile to try to recover uranium from seawater
(B) Someday, it may be worthwhile to try and recover uranium from seawater
(C) Trying to recover uranium out of seawater may someday be worthwhile
(D) To try for the recovery of uranium out of seawater may someday be worthwhile
(E) Recovering uranium from seawater may be worthwhile to try to do someday

I went for C, but the OA is A. I am still not sure why C is not a good choice.
Ob mentiond this in his post
An impersonal construction with "it" is preferred in sentences such as this one. A should be it.

I still don't get it.