Your answer will be C. Progressive verbs show shows an ongoing action at a certain point in time. Hope this helps!
The correct answer is - <span>A. It's obvious that humans will never travel to planets near even the closest stars.
</span>The word <em>obvious </em>makes us realize that this is actually somebody's opinion rather than a fact. The author didn't provide enough evidence to support this claim - and saying that something is <em>never </em>going to happen is wrong because there isn't a 100% chance they are right. Maybe some day we will travel deeper into the space - the author cannot claim this will never ever happen.