A period of hot summers will actually affect the rabbit population in a positive way. It will allow the population to increase in size and get ready for harsh weather that is to come for the rest of the year.
The first option is the correct answer, Troposphere.
Hello!
The heart is kind of like the "base" or "hub" for blood. The heart will send of blood and receive blood, and send it off again. It allows for blood to be bumped through the whole body.
I hope this helps!