GMAT Sentence Correction (SC) | Re: As the etched lines on computer memory chips have become

C is wrong because of two reasons:

1. The subject"the power of the chips ANDthe electronic devices they drive " is plural, whereas the verb "has" is singular.

2. "the chips’ circuits are more complex"..... the verb "are" is wrong, should be "have become". In Option B (OA), this correct verb is used, but omitted (correctly) to avoid repitition in parallel items.