这个题为什么E对呀？

mike125615212

37. GWD31-37E

In1994 the white house named Dr RuthR. Faden chairperson of the federal advisorycommittee of experts they assigned to do a report on the history andethics of the government’s radiation experiments on humans in the 1950’s and 1960’s .

federaladvisory committee of experts it assigned to do

it是定语从句，修饰committe，it指代白宫。Committe做assigned的宾语

A.      they assigned to do

B.      to be assigned doing

C.      that was being assigneddoing

D.     ! assigned for doing

E.      it assigned to do  

mike125615212