Final answer:
Accurate threat categories are External and Internal, and Intentional and Accidental. For the pet trade, habitat loss and overharvesting are direct extinction risks. Lightning and pollution exemplify natural and human-related disturbances of concern to conservationists.
Step-by-step explanation:
Accurate pairings of threat categories would be A. External and Internal and C. Intentional and Accidental. These categories accurately describe sources and types of threats that can impact systems, organisms, or environments. External threats are from sources outside the system, while internal threats arise from within it. Intentional threats are those that are deliberate, whereas accidental threats happen without purpose.
In the context of extinction risks related to the pet trade, b. habitat loss and overharvesting may be a direct result. The pet trade can drive overharvesting, where species are removed from their natural habitats at unsustainable rates, and habitat loss, as environments are altered or destroyed to capture these species. Both of these threats are significant concerns to conservationists because they can lead to a decrease in biodiversity, disrupt ecosystems, and ultimately risk the extinction of species.
Similarly, conservationists are concerned about both natural disturbances, like lightning, and human-related disturbances, such as pollution. These disturbances can have profound effects on ecosystems, impacting species survival and the health of the environment. Therefore, understanding and mitigating these threats is a key part of conservation efforts.