Yes i have an grammar section on my book and i learnd about run-on. I didn’t seen the run on on the answer B, but now i can see it.
In the sentence “Marie aime les croissants son chat préfère du lait” i would choose the conjonction “Mais” “or” ,“Et” or a period. In french we have the mnemonic for the conjunctions “mais ou est donc Ornicar ?” And in English i learnd in my book “Fanboys”
Do you speak french ? Because i have trouble with the first answer choice. When i translate the sentence in french in my head it’s sound faulse.
The translation for me is : Les étudiants voient souvent les théoremes complexe de physique et ennuyeux, sans savoir…