The correct option is D 5th
Extinction of a species refers to complete disappearance of all members of a species from every part of the planet. Since the origin and diversification of life on earth, there have been 5 episodes of mass extinctions that the world has witnessed and the sixth one is in progress. Mass extinctions completely wipe away the existing species on a planet in a very short period of time.
The extinction of all species of dinosaurs was a part of the 5th mass extinction or the Cretaceous-Paleogene extinction. It is believed to be caused by a massive asteroid hit which would have ejected massive amounts of debris, leading to global temperature drop, acid rains, tsunamis, fires, etc. The effect was the extinction of all dinosaurs and around 76% of all species on earth.
The 1st mass extinction (Ordovician-Silurian extinction) probably occurred around 440 million years ago that led to the extinction of many small marine creatures. Around 85% of all species became extinct.
The 2nd or the Late Devonian extinction occurred around 365 million years ago. About 75% of all species became extinct and wiped away most marine invertebrates.
The 3rd or the Permian-Triassic extinction occurred around 250 million years ago. Around 96% of all species became extinct and most vertebrate species were wiped off the surface of earth.
The 4th or the Triassic-Jurassic extinction occurred around 200 million years ago. Around 80% of all species became extinct.
The sixth mass extinction is in progress and is due to human activities. It is happening at a very fast pace and is 100 to 1,000 times faster than in the pre-human times.