As exit polls are used to project the winners of an election, sometime

AS construction: AS I had walked, I became more nervous. ( i.e. Subject should follow after the comma)

(A) As exit polls are used to project the winners of an election, sometimes appearing before all the polling stations are closed, this results in their premature release influencing
"this" is almost always used as an adjective in GMAT, for e.g. this pen, this car, etc.

(B) Exit polls, used for projecting an election's winners and sometimes appearing before polling stations are closed, result in their premature release influencing -
If we ignore modifier, the sentence becomes: Exit polls result in exit polls(their) premature release influencing...

(C) Used to project the winners of an election, exit polls sometimes appear before all the polling stations are closed with the result that their premature release influences - Correct but can be made better with a comma before "with the result.."

(D) Exit polls used to project an election's winner sometimes appear before all the polling stations are closed, with the result that their premature
release influences - IMO "used to project an election's winner" should be non essential modifier in this case. Subject and the verb seem too far.

(E) As exit polls used to project an election's winner sometimes appear before all the polling stations are closed, with the result that their premature release influences - There is no independent clause in the sentence.