What is extinction?
Your own word

I hope this helps :)

Explanation:

Extiction is where certain species or race no longer exists. Like a sabor tooth tiger, you wont see none of those around, because they are extinct.

extinction in my own words is a loss of species, for example the dinosaurs weather some people think there real or not they went extinct many animals are going extinct everyday because of poachers or just a loss of habitat, but extinction is when u think about kind of hard to say because we could say that there is a species of an orange bird that has gone extinct but then out of no where scientist suddenly confirm that there is a whole island of orange birds so in conclusion I think extinction is the sudden loss of a species due to their surrounding and habitats

sorry is this is wrong correct me in the comments if so

i think that d. wind is the answer.   i missed the question when i answered a. currents.

thinking it would be physical characteristics