Question

which characteristic of blood determines if it is considered ‘positive’ or ‘negative’?
a type a
b type b
c type ab
d type o
e rh factor

Explanation:

Blood type positivity or negativity (e.g., A+, B -) is determined by the presence or absence of the Rh factor (a protein on red blood cells). Options A - D (Type A, B, AB, O) refer to ABO blood grouping, not the positive/negative designation. The Rh factor (option E) is what determines if blood is positive (has Rh factor) or negative (lacks it).

Answer:

E. Rh factor