PREP语法笔记的笔误……？请教！！！

83. (28949-!-item-!-188;#058&004110)
The number of plant and animal species that humans are known to have forced to extinction in the last half millennium is over 800.
(A) humans are known to have forced to extinction
(B) humans are known as having forced to become extinct
(C) humans are known for forcing to become extinct
(D) are known that humans forced to become extinct
(E) are known as having been forced to extinction by humans

A. 正确，完成时态突出了“已经”灭绝的含义。
B. Be known as用于此处语义不正确
C. Be known for用于此处语义不正确
D. That are known that… 表达笨拙
E. Be known as用于此处语义不正确；having been forced表达笨拙
句子结构：The number of… is over 800. 为句子主结构。
划线部分为句子限定性定语从句，修饰species，表示人们知道的已经绝种的动物和植物的数量为800种。在定语从句中，that指代plant and animal species，做从句have forced的宾语，而不是从句主语。从句还原之后正常语序形式为：humans are known to have force that (指代plant and animal species) to extinction….

句子结构（Grammatical Construction）, 习惯用语（Idiom）
1) that指代species在定语从句中作known的宾语
2) be known to do something为正确的习语，Be known as…作为…而著名，know for…表示以…而著名，或而被别人认知。

红字部分，都是在解释that的指代，一个说that做have forced的宾语，而下面这个说that做known的宾语，这不是明显是paradox吗？？？

另外，正确选项A中，(A) humans are known to have forced to extinction，
既然that这里做force的宾语，那还原之后就是：humans are known to have forced that (=plant and animal species) to extinction，但是extinction只是一个名词，而一般来说force sb to do sth，这里to后应该加上一个动词原形而不是名词！所以A选项也是有点问题的？？（TO在这里不是介词啊，怎么能直接加上个N？）

请NN指教！

是啊，这题我也很困惑，选的时候是实在是没得选了最后选的A