Answer:
2. the line separating Australian animal species from non-Australian species
Explanation:
The Wallace line is an animal boundary line drawn by Alfred Wallace that separates Australian fauna species from non-Australian fauna species. It's a transitional zone between Austrialia and the Asia continent. The animals found in south East Asia is so much different from those found in Australia, hence the line drawn. The line is just one of the many biogeographical borders in the world separating geographical regions with not so similar group of plants and animals.
The Atlantic Ocean is the answer to the question.
Because if the axis wasn't tilted the sun wouldn't shine on the top of the earth.
