Defying efforts by policymakers on both sides of the Atlantic at restraining it, the United States dollar, continuing its rise, reaching its highest level in six years against the German mark.
(A) at restraining it, the United States dollar, continuing its rise, reaching -
Wrong Idiom. Fragment, no verb
(B) at restraining it, the rise of the United States dollar continued, to reach
Wrong Idiom- to+v ( No intention is required in a sentence )
(C) at restraining it, the United States dollar continued rising, and it reached
Wrong Idiom, 2ND IT - Redundant, therefore not parallel
(D) to restrain it, the United States dollar continued its rise, reaching
Perfect - Idiomatic , ING modifier used correctly
(E) to restrain it, the United States dollar is continuing its rise, and to reach ( Not parallel )