Could you please provide your comments for option E? how do we know that action is completed. According to statement given in question no where we know that action is completed. We can also say action is going on and dollor is to reach its highest level in six years against the German mark.
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
(B) at restraining it, the rise of the United States dollar continued, to reach
(C) at restraining it, the United States dollar continued rising, and it reached
(D) to restrain it, the United States dollar continued its rise, reaching
(E) to restrain it, the United States dollar is continuing its rise, and to reach
I see "it" so awkard, but ....
