highgmat

i would choose C as the best answer.

highgmat

i would translate the sentence into chinese, then you will see.

马科尼曾经考虑把无线电作为一种可以替代电话的私人交谈工具；但事实上恰恰相反，无线电成为了大众传媒工具。

C表达的意思是最通顺的。

E的表达有两处非常蹩脚的地方，尤其是“other than what it is”