Name two possible causes of the largest mass extinction in Earth’s history and explain how this both helped and hurt different species.

Explanation:

Two possible causes for the biggest mass extinction event in the history of our planet would be an asteroid impacting the planet and the massive volcanic activity. This mass extinction event is called the Permian-Triassic extinction. This helped many species emerge as survivors and thrive without the oppressive bigger species that died out. It hurt many species that were unable to survive the harsh conditions that resulted from everything that was happening to their habitats and food sources.

it is either c or d and i know for sure it is not a or b

this is true, assuming that the allele is completely recessive and incomplete dominance is not a factor.