【单选题】

Educators who study the influences of geographical differences on educational success have concluded that environment is not ------- factor, as students in one country are no more ------- than those in another.
A．(A) an essential .,. erudite

B．(B) a determining ... preeminent
C．(C) a pernicious ... mediocre
D．(D) a conducive ... meritorious
E．(E) a wholesome ... susceptible