Please choose the correct answer to the question: A person cuts down their neighbor's tree without permission. The neighbor who lost the tree is upset, and sues for the cost of the tree, which depends on the age of the tree at the time of cutting. The tree age is determined by

Answer1: size of branches Answer2: number of leaves Answer3: color of roots Answer4: number of circles

Answer format: answer1/answer2/answer3/answer4
Answer: answer4