D. Son tools on the Internet which allow stuff about the universe
Comida<span> grasosa (</span>tiene<span> mucha </span>grasa<span>, propia y añadida) Alimentos grasos (tienen mucha </span>grasa<span> propia).</span>
No.
you use the subjunctive the talking about things that aren't facts or certain, like emotions, suggestions, doubt, etc.
for example, if i were to say "yo pienso que tu debas estudiar" (i think that you should study), just because i think you SHOULD study doesn't mean that you actually will, thus making it subjunctive
Hope this helps :)