Answer the following question: You are presented with the quiz "What usually changes in the autumn season?" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "the color of leaves on deciduous trees usually changes in the autumn season" and "deciduous trees are Oak, Elm, Ash, Maple, and Birch". So, what's the best answer to the question?

Available options: 1). Something that can be auburn 2). looseness of dirt or compost 3). the looseness of soil 4). the color of leaves on oaks 5). a hemisphere is tilted away from the sun 6). Warm air moving into cold air 7). the male sex cells of plants 8). The bending of a ray of light
Answer:
4).