Please choose the correct answer to the question: In 1872, the United States created a national park called Yellowstone. The park includes more than two million acres in the three states of Idaho, Montana, and Wyoming. Which statement best explains why national parks have a positive effect on ecosystems?

Answer1: National parks limit people from seeing wildlife. Answer2: National parks limit mining, logging, and hunting. Answer3: National parks protect land for farmers and ranchers. Answer4: National parks protect land for people to build houses.

Answer format: answer1/answer2/answer3/answer4