To answer this question, you need to understand the concept of blood types and compatibility.
There are four main blood types: A, B, AB, and O. Each blood type can be either positive (+) or negative (-) based on the presence or absence of the Rh factor.
The correct answer is C) O. Blood type O is known as the universal donor because it can be given to individuals of any blood type (A, B, AB, or O) without causing an adverse reaction. This is because blood type O lacks both the A and B antigens on the red blood cells, which means it does not trigger an immune response in the recipient.