Answer:
Natural Selection.Explanation:
One such situation would be Natural Selection. This involves the weaker individuals of a population dying off while the stronger ones continue living long enough to reproduce and pass on their stronger genes. This occurs naturally in every species and determines how a species evolves over time, therefore providing very valuable information. However, performing this as an experiment would involve killing off the weaker portion of a population or allowing them to die which would be unethical.
In today's society, the answer is D.) Communism, socialism, and capitalism.
Examples are Capitalism (United States), Communism (Russia), and Socialism (Cuba).
You would need to take a Recreational Therapist Careers course to be part of recreation in a long-term care facility.