看前辈帖子发现一道so...as to的题有问题（？？？）

In the Renaissance, painters were so impressed with Leonardo da Vinci that they ignored their own training and designate as a masterpiece anything he painted.
(A) were so impressed with Leonardo da Vinci that they ignored
(B) were impressed with Leonardo da Vinci to such an extent that they were to ignore
(C) were so impressed with Leonardo da Vinci as to ignore
(D) were so impressed with Leonardo da Vinci that they had to ignore
(E) were as impressed with Leonardo da Vinci as to ignore

Answer is C 
            

答案怎么会选C呢？我觉得A比C好- C 用 so... as to后面的逻辑主语有歧义啊- 有可能是painter也有可能是达芬奇ignore（？）

如果是因为时态要和designate对应的话，我觉得这个错误还没有C无逻辑主语来的明显...

请大家指教！

so as to只需要一个主语就够 to后面的主语和前面的一样

关键就在于designate 不然A也正确