请教：原句错在哪呢？（新东方蓝皮一题）

Although dozens of New York's small museums are either devoted to local history or various ethnic groups, there are many one-of-a-kind museums from Manhattan to the Bronx that are open for exploration on summer weekends.

A)Although dozens of New York's small museums are either devoted to local history or various ethnic groups, there are

B)Although dozens of New York's small museums are  devoted to local history or various ethnic groups,

C) Dozens of New York's small museums are devoted to local history or various ethnic groups, but there are

D)Dozens of New York's small museums are devoted to local history or various ethnic groups, and  there are also

E)Devoted to local history or various ethnic groups, dozens of New York's small museums and also

答案是D,可是A错在哪里呢？