While some market research suggests that customers prefer to purchase text messaging plans as part of an all-inclusive cell phone service package, other studies have found that customers will buy a text messaging plan only if it would be offered as a separately optional feature.


(A) only if it would be offered as a separately optional feature

(B) only if it is offered as a separate, optional feature

(C) if it is offered only as an optional feature separately

(D) if it was offered only as a separate and optional feature

(E) if it would only be offered as an optional feature, separately