The correct answer is D. 1,000.
Bats account for almost a quarter of all mammal species.
They are found everywhere on earth except in the most extreme desert and polar regions. Some forty species live here in the United States and in Canada, but the majority inhabit tropical forests. And almost all of these species are highly benefical. A single brown bat can catch 600 mosquitoes in just one hour. Bet you'd welcome a few more of those around on a hot summer evening.