To tackle the issue of Congressional campaign spending is becoming embroiled in a war which is raging between those who support public financing with those who would lift the limits on the amount political parties and individuals may donate.

(A) becoming embroiled in a war which is raging between those who support public financing with
(B) becoming embroiled in a war raging among those who support public financing with
(C) to become embroiled in a war raging between those who support public financing and
(D) to become embroiled in a war which is raging among those who support public financing and
(E) becoming embroiled in a war raging between those who support public financing and

OA C

Why is E wrong. The OA was a bit confusing .
[spoiler]Why To tackle needs to be made parallel to become ?[/spoiler]