A) Problem One

Well first of all I'll consider my possibles variables, that in this problem the most important is MONEY. Other variables are that my friends are sick and that University has already started. Taking in consideration University I would say that it's better to study a carrer in Denmark. There are more oportunities and much more chances. If I return to Aguascalientes maybe I would lose most of the course, I would lose money in returning and, in my opinion, if we are talking about "study" I would stay in Denmark and enter to a Danish University and start working because I don't have money. In the worst case would be that I dont' study so dedicate all my time in get a job and work to earn the enough money to get back and then enter the next year to continue my University in Ags.
About my friends, I think there's no problem about it. In my opinion, I do not depend on them. It would not affect me if they are ill or if they are not.
About money! that's the big deal... If I get back to Ags I would lose a lot of money, I'm broke and I don't think I could get back. Maybe if I stay in Denmark for a while, I will work, I will earn money there and about my studies I could take a course there or wait until I get back to Ags.
So my desicion would be stay in Denmark defenitely. I don't have money to get back, In Denmark I can get a job and get some money.