The fact thatthey reacted so differently was a reflection of their different _______.
B. preferences
C. personalities
请问各位老师，这题为何不选preferences呢？谢谢老师！
The fact that they reacted so differently was a reflection of their different personalities.
参考译文：他们反应的巨大差异的这个事实反映了/表现出了他们不一样的个性/性格。
备注：依据句子所表达的意思是“不一样的个性/性格” 而不是说的“偏好/偏爱”，所以用personality.
personality 个性；性格;人格
His wife has a strong personality.他老婆的个性非常强。
The children all have very different personalities.孩子们的性格特点各不相同。
He maintained order by sheer force of personality.他纯凭人格力量维护秩序。
preference n.偏爱；喜好；喜欢
It's a matter of personal preference .那是个人的喜好问题。
Many people expressed a strong preference for the original plan.很多人强烈表示喜欢原计划。
I can't say that I have any particular preference.我说不源于己有哪些特别偏好。
