Answer:
B. very high genetic variation
Explanation:
Selective breeding is the process by which crops or animals with desired phenotypic traits are chosen to produce offspring, which will contain the desired qualities. In this case, a group of scientists is trying to apply the principles of selective breeding to develop a particular crop plant.
This goal of producing a useful crop plant by the scientists can only be achieved when the plant species in question possess a HIGH GENETIC VARIATION i.e. difference in genetic constitution of individuals of the same species. This allows the individuals in the population to survive better.
While there is no graph provided and I cannot find the graph online, I will base my answer through theory.
In theory, the most common blood type is O+, followed by A+, then B+, then AB+. Rh negative blood is deemed to be rare. While the most common blood type is O+, the same blood type is also called the "universal donor" as a type O+ blood has no antigens attached in red blood cells therefore the probability of adverse reactions (i.e. hemolytic reactions) when transfused to other blood types are close to nil. In an emergency situation, wherein there is not enough time to do proper crossmatching, blood type O+ can be used therefore supplies of blood type O+ are easily depleted.
The two-layered sac surrounding the heart is the pericardium.
Hope this helps!
