1.(With one) of the most successful African American business in history,the MR Corporation was founded in 1959 in Detro

1.(With one) of the most successful African American business in history,the MR Corporation was founded in 1959 in Detroit by Berry Gordy,Jr.
A.不改动；B.It was one; C.Being one; D.One; E.As one
但c和e为什么不行?答案说c和e与MR Corporation这个名词成分不平行,这里还要考虑平行吗?
2改句子：Although long considered a vestigial organ that has no function in humans,(the appendix,some scientists believe,may have) a significant role as part of the body's immune system.
正确答案是a,就是不改动
我选的是b：改成：the appendix,which,some scientists believe,may have
答案说b的话,句子就没动词,但which,some scientists believe,不是插入语吗?所以动词是may 反而a我觉得错是因为有2个动词啊：believe和may（就算some scientists believe是插入语,which指代appendix啊,然后动词是may have）