An enormous rifting occurred, causing massive floods of basaltic lavas and the release of large amounts of gas. this is thought to have been the cause of which mass extinction?
1) cretaceous-tertiary
2) end triassic
3) permian-triassic
4) late devonian
5) ordovician-silurian

2) End Triassic

Explanation:

End Triassic extinction occurred 201 million years ago. It was caused by the rifting of super continent Pangea. Pangea started to break and drift apart. When North america started to separate from Africa, volcanic activity increased. Lava and a large amount of gas was released into the atmosphere specially carbon dioxide. This led to global warming like condition which ultimately caused extinction of a large number of species.

i think that the best answer would be c.

tell me if im wrong : )

if the type of the food available changes, then the frequency of beak types will change, because birds with beaks more suited to the available food will be more successful over time.