Genghis Khan's Mongol empire was, at its peak, considerably larger than Attila's Hunnish empire, but because Attila's home base, in modern Hungary, much closer to Western Europe than Genghis' Mongolian headquarters, Genghis posing less of a threat to Rome.
(A) much closer to Western Europe than Genghis' Mongolian headquarters, Genghis posing
(B) much closer to Western Europe than to Genghis' Mongolian headquarters, Genghis posing
(C) much closer to Western Europe than was Genghis' Mongolian headquarters, Genghis posed
(D) was much closer to Western Europe than was Genghis' Mongolian headquarters, Genghis posed
(E) was much closer to Western Europe than Genghis' Mongolian headquarters, Genghis posed