The answer is D. Instinct
Eagles evolved better over the years to hunt their targets easier, which explains why they have sharp talons, they instinctively use them to hunt their prey.
Examples of a scientific theory
Scientific theories are testable and make falsifiable predictions. They describe the causes of a particular natural phenomenon and are used to explain and predict aspects of the physical universe or specific areas of inquiry (for example, electricity, chemistry, and astronomy).
When in space it is a meteorite. When it is entering the atmosphere, it is a meteor. When it hits the earth it;s classified as a meteoroid.
Hope this helps.
Explanation:
The pulmonary valve (sometimes referred to as the pulmonic valve) is a valve of the heart that lies between the right ventricle and the pulmonary artery and has three cusps. It is one of the four valves of the heart and one of the two semilunar valves, the other being the aortic valve. Similar to the aortic valve, the pulmonary valve opens in ventricular systole, when the pressure in the right ventricle rises above the pressure in the pulmonary artery. At the end of ventricular systole, when the pressure in the right ventricle falls rapidly, the pressure in the pulmonary artery will close the pulmonary valve.
