Question

which global occurrence is most supported by evidence to be the cause of the mass extinction of a large number of dinosaur species at the geological time boundary between the mesozoic era and the cenozoic era?
asteroid/comet impact
global glaciation
continental collisions
earthquakes and volcanism

Explanation:

The mass extinction of dinosaurs at the boundary between the Mesozoic and Cenozoic Eras is most supported by evidence of an asteroid/comet impact. The Chicxulub crater in Mexico is a key piece of evidence. It is dated to the same time as the dinosaur extinction. The impact would have caused global climate change, wildfires, and other catastrophic events that led to the extinction.

Answer:

asteroid/comet impact.