excellent explanantion by NUSMAVRIK .....
A resumptive modifier picks up a word or phrase from a sentence that seems to be
finished and then adds information and takes the reader into new territory of thought.
Since the 1930’s aircraft manufacturers have tried to build airplanes with frictionless
wings, shaped so smoothly and perfectly that the air passing over them would not
(A) wings, shaped so smoothly and perfectly
(B) wings, wings so smooth and so perfectly shaped
(C) wings that are shaped so smooth and perfect
(D) wings, shaped in such a smooth and perfect manner
(E) wings, wings having been shaped smoothly and perfectly so
OA : B
Wings is required to unambiguously convey the meaning of the sentence. It is the wings that are shaped so perfectly and smoothly (adjective). Note how the subject "wings" is unambiguously and descriptively modified in B. Whereas A has ambiguity - it can modify "airplanes" instead of "wings".
trace the link to understand the full dicussion ....sc-ets-i-doubt-the-answer-98355.html?hilit=wings#p758998