试着分析一下吧
Ａ，but it ...., the Erie Canal connected,两个独立的句子中间应该有连词或分号隔开
B,12 feet deep but running 363 miles 有点怪，但也说不上错，我选Ｂ
Ｃ， It was seldom more than 40 feet wide and 12 feet deep, and ran 363 miles across the rugged wilderness of upstate New York, but the Erie Canal, connecting. but后应该是一个完整的句子，并且and前后是反向对比关系，应该用but才对。
ＤThe Erie Canal was seldom more than 40 feet wide or 12 feet deep and it ran 363 miles across the rugged wilderness of upstate New York, which connected
it多余，并且前边不应用and（如Ｃ），which指代不清
Ｅ，缺谓语动词 | 
