[SC悬赏令] what指代问题

The ancientAnasazi harvested such native desert vegetation as the purple-flowered beeplant, what they now commonly call wild spinach in northern Arizona andother parts of the southwestern United States.

A.    what they now commonly call--------------------------

B.    a plant that they now commonly call------------------为什么这个不行？？？？

C.    now commonly called------------------------------------

D.   and is mow commonly called---------------------------

E.    which it is now commonly called-----------------------为什么这个不行？？？