Question

at the end of the mesozoic era there was a mass extinction. which of the following is attributed as being the main cause?
asteroid or comet impact
major volcanic eruption
earthquakes
climatic changes

Explanation:

The leading scientific consensus, supported by evidence like the Chicxulub crater and iridium layer in geological records, identifies an extraterrestrial impact as the primary trigger for the end-Mesozoic (Cretaceous-Paleogene) mass extinction. While other factors may have contributed, the impact is the widely accepted main cause.

Answer:

asteroid or comet impact