Advise, please?

Today there was a little dispute with our English teacher, regarding a certain assignment where we were supposed to add an article to a sentence. (she said one way to write it was the best, while most of the class disagreed)
So, my dear friendslist, which one do you think is better? Or are both equally good and mean the same thing?

Her tasks include the production of advertising material and assisting the sales offices in Finland and the UK
or
and the assisting sales offices in Finland and the UK