Please choose the correct answer to the question: A researcher observes that an organism placed in a glass container filled with water moves away when a penlight is focused on the container. The researcher concludes that the organism is light sensitive. Which other explanation for the organism's response to the light is most possible?

Answer1: The organism avoids radio waves. Answer2: The organism avoids gamma rays. Answer3: The organism moves away from vibrations. Answer4: The organism moves away from heat sources.

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