GMAT Sentence Correction (SC) | Re: In the major cities of industrialized countries at the end

In the major cities of industrialized countries at the end of the nineteenth century, important public places such as theaters, restaurants, shops, and banks had installed electric lighting, butelectricity was in less than one percent of homes, where lighting was still provided mainly by candles or gas.

A. electricity was in less than one percent of homes, where lighting was still

B. electricity was in less than one percent of homesand lighting still
--> parallelism issue.

C.there were
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