Question

which of the following is not considered a likely cause of the permian - triassic extinction? a.) a supernova b.) volcanic eruptions c.) increasing carbon dioxide levels d.) an asteroid impact

Explanation:

The Permian - Triassic extinction is thought to be mainly due to massive volcanic eruptions in the Siberian Traps, which led to increasing carbon - dioxide levels and climate change. An asteroid impact is also considered a possible but less likely cause compared to volcanic activity. A supernova explosion at a close enough range to Earth would be catastrophic, but there is no evidence that a supernova was involved in the Permian - Triassic extinction.

Answer:

a. A supernova