Why might dinosaurs have become extinct

One, by the predicted mega Meteor that hit earth which changed everything, maybe of food scarcity and ended up either eating each other up or died due to starvation, Perhaps maybe even a black plague or some other virus/ disease, Volcanoes, Earthquakes, Tsunamis, Flooding, and Droughts

Explanation:

These are all guesses and none of them might be true, im just going off of several terrestrial bodies that could wipe out dinosaurs.