6. during the permian mass extinction: a) oxygen levels in the deep oceans dropped b) global warming occurred as a result of volcanic eruptions c) a meteorite hit the earth d) both a & b are correct. e) a, b & c are all correct.

E) A, B & C are all correct.

Explanation:

During the Permian mass extinction also known as the great dying, comprising 96% of marine species and 70% of the terrestrial vertebrates became extinct.  Possibly much loss of biodiversity due to the major events like the large meteor impacts, massive volcanic eruptions, associated with climate changes that brought large underwater methane gases into action. It took place about approximately 252 million years ago. Release of various harmful gases like Hydrogen sulfide and the Siberian Traps eruptions.

Answerwill have thinner; have thicker oceanic sediments;

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