Answer:
a. 10 species per day
Explanation:
The current rates of extinction are incredibly high, much higher than what is the natural average of extinction of the species. Even though it stands that around 10 species are getting extinct every day, there's many clues that suggest that the number reaches incredible 150-200 species per day. This just backs up the statements of numerous scientists that we are actually creating the sixth mass extinction that Earth has experienced, as such rates of loss of species are typical only for mass extinctions.