"Young adults do not often read the newspaper."
Translation:Les jeunes adultes ne lisent pas souvent le journal.
Short adverbs that modify a verb usually follow the conjugated verb. If the verb is negative, the adverb is placed after the negation.
Long adverbs are usually placed at the beginning or end of the sentence. However, if the long adverb specifically modifies the verb, it is placed after the conjugated verb.
Interpretation question: le journal would normally mean a specific (the one and only for some given context) newspaper. But this sentence as a whole implies -- to me at least -- a generalization applying to any and all newspapers. So, and given the negation here, why isn't de journal used?
You marked my answer correct; it was the same as the one you listed, but I, too, think it probably is more typical for the French to use "des." In other words, since leaving out the word "souvent" would force the word "de" in front of "journal," instead of "le" - then what do we gain from what seems to be a more word for word translation than you would get not using the word "often."