[OldBlondBabe]

"I thought O was the most common blood type?"

I believe "B" is the most common. O (especially O-) is most often requested because it is universal. It can be given successfully to those with all the other blood types: A, B, AB and O, both RH positive and negative can be given O-.

[MarMema]

O is the most common blood type. O positive, with roughly 40% of the population. Then comes A positive with something like 30% of the population. B is fairly rare.

I do a lot of blood banking...

[Nothometoday]

I am sorry...But I do thank you for all the answers.