In many upper-class Egyptian homes, French was spoken within the family, just as it had once been among the Russian aristocracy.

(A) just as it had once been among the Russian aristocracy
(B) just like it once had been among the Russian aristocracy
(C) just as the Russian aristocracy had once done
(D) similar to what the Russian aristocracy had done once
(E) like what had once been done by the Russian aristocracy

Please explain the difference between A and C

Thanks.

OA A