Why is the blood group 'O' called as universal donor?

Why is a person having blood group AB called universal recipient and a person with blood group O called a universal donor?

Which blood group is called universal donor ?

Why are people with O blood group called as universal donors?

Which blood group is called Universal donor?

Why is person with O-blood group called universal donor?

_____blood group is called universal donor.

Which type of blood group is called universal donor?

The blood group ________ is called universal donor.

Give reason: People with O^- blood group are called universal donor.