各位大大好，小弟在做陈圣元的时候遇到一题想不通的题目，敢请大家解惑。
The notion that cultural and biological influences ____ determine cross-cultural diversity is discredited by the fact that , in countless aspects of human existence , it is cultural programming that overwhelmingly accounts for cross-population variance.
(A) jointly
(B) completely
(C) directly
(D) equally
(E) eventually
答案是说要选D，但我觉得A应该也可以啊，请问一下为啥A不行？