请教XDF教材，P130-86 (PartII)，正确答案关于同类比较的的合理性

P130-86 (PartII)

In his eagerness to find a city wothy of Priam,the German archeelogist Schelieman cut through Troy and uncovered a civilization a thousand years older as it was the city Homer's heros knew.

A. older as was the city Homer's heros knew

B. more ancient than the city known to Homer's heroes

C.older than was the city known to Homer's heroes

D.more ancient of a city than Homer's heroes knew

E.older of a city than was the one known to Hormer's heroes

我的思路是：more ancient 优于 older,所以排除了A,C,E， D选项than后面没有比较对象。答案是B

然而B选项似乎是拿civilzation 与 city作比较，非同类同比较啊。。。。请高人指点分析一下B选项

比较时助动词习惯补出但得补正确.

 A older as错'

C  than 出现了was错,因为谓语不是系动词

D比较对象不对等

Ewas补错了.