A-positive
From Tardis Wiki, the free Doctor Who reference
A-positive was a very common blood type on Earth.
As of 25 December 2006, about one-third of Earth's population had A-positive blood. The Sycorax used this to their advantage in their attempted invasion of the world by using blood control on all the A-positives using a vial of A-positive blood placed on the Guinevere One space probe. (TV: The Christmas Invasion)
