【单选题】

Politicians and pollsters alike warn that the outcome of a presidential race remains ------- until Election Day itself, and many races depend on factors that run from bad weather ------- voter turnout to last-minute scandals.
A．(A) unknown … abetting

B．(B) unlikely … decreasing
C．(C) fluid … affecting
D．(D) predetermined … consolidating
E．(E) fixed … absorbing