Please choose the correct answer to the question: A chemist observed bubbling and fizzing after adding an acid solution to a white powdery substance in a beaker. Which of the following can be inferred?

Answer1: The acid boiled when poured into the beaker. Answer2: The acid and powder formed a new product. Answer3: A physical reaction produced a gas mixture. Answer4: A reaction occurred that produced heat.

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