What was the most likely cause of the dinosaurs being extinct

There were two eras of dinosaurs that are supposed to have existed - the Palaeozaic era and the Mesozaic era. They were divided into certain timelines of dinosaurs called periods. Each time one period went existed, it was replaced by a different period. However, by the end of the Cretaceous period, dinosaurs did not replace them. Instead, mammals, snakes and other reptiles came to existence.

Now tell me - through guesswork and using your own creativity, do you have any idea or guess why they(the dinosaurs) suddenly went extinct?

PS... I do not want answers like 'I don't know' or no one can tell', because I just want to know what ideas mankind have about the relevant topic.

There have been many mass extinctions throughout the history of the Earth. Probably the most famous is the extinction that finally saw the end of the dinosaurs reign on the Earth, 65 million years ago. It wasn't just the dinosaurs that died out in this extinction.
The two main 'serious' theories are the asteroid and volcano theories, both of which make some use of the analysis of the rocks in and around the K-T boundary (the Cretaceous - Tertiary boundary). The use of K comes from the Greek word for chalk (Kreta) which is found in great quantities in the rocks of the Cretaceous.

Dinosaurs as a group got bigger over time until an extinction event 65 million years ago wiped out all but bird-like dinosaurs. Scientists don't agree entirely on what happened, but the extinction likely was a double or triple whammy involving an asteroid impact, choking chemicals from erupting volcanoes, climate change and possibly other factors. Some scientists are also claiming that Dinosaurs had very less resistance in their bodies,they got infected very easily from insect bites,snake bites and also by poisonous plants etc and gradually went into extinction .

In the bible there was the flood, that wiped out everything on earth except for noah, his family and 2 of each type of animal (male+female), the ark was huge but I think dinosaurs were just too big. God has a plan for everything and everyone, and that's what the plan for dinosaurs were, I guess.

Big meteor hit the earth, kicking up clouds of particles, which cut off the sun, so a lot of plants died, leaving nothing for dinosaurs to eat, and so they all died except for flying ones (birds) with the mobility to find areas with food.

they ionvented computers and a Yahoo. they spent so much time answereing Q &A that they stopped making baby dinosaures,
do not let that happen to you

It is a good Q all we can be sure of is there are no more dinaures ( unless you count the birds)
ther eare differnt theories. they have to explain why it was world wide. and not just on one continent

Theres no such things as dinosaurs. dinosaurs were invented by the CIA to discourage time travel.