Improving sentences

[Sikteen]

I am really confused with the following question of the Improving Sentences of the SAT I. Anyone can help me plz!

Pop artsist Ed Ruscha was fascinated by words, and have consistently formed the principal subject matter of his paintings.
(A) words, and have consistently formed the principal subject matter
(B) words, and words have consistently formed the principal subject matter
(C) words which have consistently formed the principal subject matter
(D) words, consistently they have formed the principal subject matter
(E) words, which have consistently formed the principal subject matter
I am thinking of the choice C

[Codename Gordon]

I think the correct answer is E because of the non-defining realtive clause. Here, you give more information about words, but it is not necessary to explain which words you mean (words in general).

[carpe]

I think the correct answer is E because of the non-defining realtive clause. Here, you give more information about words, but it is not necessary to explain which words you mean (words in general).

I agree too, I think it's E!