Please choose the correct answer to the question: A student heated a pan of soup on a stove. While stirring the soup with a metal spoon, the student noticed the spoon became very warm. What is the most likely reason the spoon became warm?

Answer1: The stirring action heated the spoon. Answer2: Warm air in the room heated the spoon. Answer3: Heat from the soup was transferred to the spoon. Answer4: The student's hand transferred heat to the spoon.

Answer format: answer1/answer2/answer3/answer4