Please choose the correct answer to the question: A student performs an experiment and the results are shown below: Before- Iron filings are brown, small, and magnetic: Copper sulfate crystals are blue, brittle, and not magnetic. After- The copper formed was reddish, solid, and not magnetic: Iron sulfide solution was colorless and not magnetic. Which statement supports that a chemical reaction took place?

Answer1: Changes in color occurred. Answer2: A new substance was formed. Answer3: A physical change in the iron occurred. Answer4: The original substances were present after.

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