Sentence Correction (SC) | Re: In 1719 the Meissen manufacturers found a way of combining kaolin

I am not convinced about A being wrong.
Had Imported in Choice D means that they stopped importing in 1719 when Manufacturers found a way to make the same thing while intended meaning from the sentence given is that they were still importing in 1719 when manufacturers found a way.
Logically speaking also, Import will not stop just because a way has been found. It will stop when Manufacturing will start.

---