HANGMAN
Explanation:: One of the eight different blood categories into which humans are separated. These categories of blood are labeled A, B, AB, or O and each of these is either Rh-positive or Rh-negative.
# Remaining Guess: 2
_ _ OO_ _ _ _ _
Choose A Letter:
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z