Task: Question Answering
Input (English): 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?  
 (A) Changes in color occurred. (B) A new substance was formed. (C) A physical change in the iron occurred. (D) The original substances were present after.
Output (English): B