Sentence Correction (SC) | Re: A powder derived from the North American Echinacea flower,

1. A powder derived from the North American Echinacea flower, which has been effective in preventing colds, is grown by many small farmers out West.

(A) A powder derived from the North American Echinacea flower, which has been effective in preventing colds,
(B) A derivative, which has been effective in preventing colds, of the North American Echinacea flower
(C) A North American Echinacea flower derivative, which has been effective in preventing colds
(D) The North American Echinacea
...

---