新东方语法教材（蓝本）Page 110, No.8

As the etched lines on computer memory chips have become thinner and the chips circuits more complex, both the power of the chips and the electronic devices they drive have vastly increased.

B) the chips circuits more complex, the power of both the chips and the electronic devices they drive has

C) the chips circuits are more complex, the power of both the chips and the electronic devices they drive has

答案是B。向大牛们请教，为什么and后不是一个完整的句子结构，与and前一致，C选项？

感谢

那位牛牛给指点一下，感谢

the chips circuits (have become) more complex, the power of both the chips and the electronic devices they drive has

==> 省略。

C 和前面不平行

感谢“我爱FB", 一针见血，很清楚。