Please choose the correct answer to the question: Kerry made a simple flashlight. She recorded the following statements in her lab book. Which statement is an inference?

Answer1: The wire was 35 cm long. Answer2: The flashlight contained a battery. Answer3: The plastic switch was better than the metal switch. Answer4: The bulb was lit for 20 minutes before it burned out.

Answer format: answer1/answer2/answer3/answer4