Final answer:
The best event that relates to the impact of human actions on the physical environment for a third-grade lesson would be the oil spill in the Gulf of Mexico. It is a direct result of human activity and demonstrates the significant interaction between humans and the environment.
Step-by-step explanation:
An appropriate event that relates to the topic of the impact of human actions on the physical environment would be D) An oil spill in the Gulf of Mexico. This event is a clear example of human activities directly affecting the environment. When discussing how human actions impact the physical environment, it is important to consider anthropogenic events—those that are caused by humans. An oil spill, such as the Deepwater Horizon spill in 2010, leads to extensive environmental damage, affecting water quality, marine life, and local economies which rely on fishing and tourism. It showcases the interactions between humans and the physical environment and allows students to analyze the consequences of such interactions.
Through the exploration of this incident, various elements of environmental science and ecology can be examined, including biogeography, biodegradation, and ecological successions. This human-induced disaster also serves to illustrate the differences between anthropogenic events and natural occurrences like El Niño, earthquakes, and hurricanes.