The kinetic energy of an object depends on both its mass and its speed. Kinetic energy increased as mass and speed are increased.
        
             
        
        
        
Answer:
The correct answer is: D. Ebola.
Explanation:
- Ebola Virus is a single-stranded RNA (ribonucleic acid) virus.
- The natural host of the virus is Fruit bat but it can also infect humans.
- The transmission of the virus into humans is mediated from infected bats through body fluids.
- The major disease caused by the virus is is Hemorrhagic fever. In this disease, the platelet (responsible for clotting of blood) count in the blood  drops far below normal. As a result, bleeding can get initiated both in the body interior or exterior. This disease can cause multiple organ failure and death.
- Recently, in the year 2018, the Central African country, Democratic Republic of Congo experienced a severely fatal endemic due to the Ebola virus that killed many people within a short period of time.
 
        
             
        
        
        
The question is asking the determine the role that the United States do in the ecosystem base on the passage and situation in the question that you have state, base on my research, I would say that its role is a Dominant. I hope you are satisfied with my answer and feel free to ask for more if you have question and further clarification