What is the Blood Group of a Vampire?

It was around 10:30 P.M. in the night. I was watching the recent Hindi movie, 'Mattru Ki Bijali Ka Mandola'  along with some friends. It was movie and in the night, first night went off well.
It is a tendency in theater to show trailer of upcoming movies during the interval.  Here it goes, trailer of soon to be arrived movie 'Dyaan' (means Witch). For me the movie name was hardly important, but what important was that all that connection with her family members. Do you know anyone of these?

Needless to say, its 'Vampire' which is the most popular among his family members. Now what exactly is that? According to definitions of many movies come on this creature (guess they are  human beings), they got special powers and cant eat anything. First guess, would be they won't have any teeth?
Well, these creature have lot of teeth but they prefer to eat blood of people or say Human Beings. If I have to believe to movies, they do this for surviving. Drinking blood of different beings.. Wait a minute. How can they survive then?

You must be thinking I am crazy to ask this question. But I have an scientific explanation. Every person has a blood group determines from some testing (or may be some other methods in ancient times). The two different blood group can not stay together, except in two exception. Either the person must be a universal donor or he has to be a universal receiver in context of his blood group. Wait wait.. Don't think about blood group because we are talking about Vampires here.

So, getting back to our initial point. Let me assume that vampires are some sort of human beings (even partially), and they possess some sort of blood groups, then there must be some problems among them before they start drinking other people's blood. Some them are:
a)They should know the blood group of person they are planning to drink the blood, any mismatch can be dangerous :D
b) Or they find only universal donor, which is hard to find as people with  such blood group are very less in this planet.
c) Or their own blood group is universal receiver, causing them no problems at all.

That lead to a very difficult choice for Vampires, I can imagine they need some sort of search engine to identify their targets to feed themselves in a sustainable way.  They may chose to live but with certain conditions. Since, the movies with Vampire are always popular, making them livable on this planet. It is safe to conclude that option 'C' given above holds true in light of such developments.

So next time you are watching such horror movies where Vampire family is also present, may be you should try to find out, 'What is the blood group of a Vampire?' and you may have a reason to worry or reason to smile, Why? Figure it out yourself.
In case you get the answer, let me know too :)