Answer: Joanna is walking back to the office after her lunch break. On the way, she sees a homeless man and offers him the evening snack she had bought for herself. In this case, joanna is displaying an altruistic behavior.
Step-by-step explanation: The adjective "altruistic" is used to describe someone as unselfish. In other words, it is used to refer to someone that is willing to help others for pure concern and without waiting for anything in exchange. Therefore, Joanna displays an altruistic behavior by helping and offering food to a person in need without expecting to receive anything in exchange. By doing it, Joanna only seeks to benefit another person that is not herself.