Final answer:
Option A, blood type, is the most useful characteristic in helping identify the suspect from a genetics report.
Step-by-step explanation:
Blood type is a unique identifier: Blood types are determined by specific proteins present on the surface of red blood cells and are inherited from parents. This means each individual has a unique blood type that can be used for identification purposes.
Highly accurate: Unlike hair color and eye color, which can vary depending on lighting and other factors, blood types are relatively stable and unchanging. This makes them reliable for identification.
Widely used in forensic investigations: Blood typing is a well-established and widely used technique in forensic investigations due to its accuracy and reliability.
While hair color and eye color can be helpful in narrowing down the suspect pool, they are not as unique or reliable as blood type.
Therefore, option A, blood type, is the most useful characteristic in helping identify the suspect from a genetics report.