Please choose the correct answer to the question: Which distance is the smallest for which it is most practical to use the light-year as a unit of measurement?

Answer1: the distance between Earth and its Moon Answer2: the distance between Jupiter and the Sun Answer3: the distance between the Milky Way and the nearest galaxy Answer4: the distance between the Sun and the center of the Milky Way

Answer format: answer1/answer2/answer3/answer4