Position of "both" + S-V agreement

[limestone]

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.

A.
B. the chip's circuits more complex, the power of both the chips and the electronic devices they drive has
C. the chip's circuits are more complex, both the power of the chips and the electronic devices they drive has
D. their circuits are more complex, the power of both the chips and the electronic devices they drive have
E. their circuits more complex, both the power of the chips and the electronic devices they drive have

[spoiler]OA: later[/spoiler]

[paddle_sweep]

I will go with 'A'. Pls post OA.

[limestone]

OA is B. I chose C. Could you please explain why we can omit "are" in C?

[anantbhatia]

A, D , E eliminiated because they don't have :-

powers .. have increased

betweeen (B) and (C),

(C) should have been something like
both the power of X and that of Y

So B is correct.