Final answer:
The presence of the same type of blood protein, hemoglobin, in different species of organisms indicates that B. species share a common ancestor.
Step-by-step explanation:
The presence of the same type of blood protein, hemoglobin, in different species of organisms indicates that species share a common ancestor. Hemoglobin is essential for oxygen transport in the blood and is found in all vertebrates.
This shared characteristic suggests that all vertebrates, including humans, evolved from a common ancestor that had hemoglobin. The presence of homologous genes coding for the carbohydrates on the surfaces of red blood cells further supports the idea of a common ancestor for these genes. Therefore, the correct answer is B - species share a common ancestor.