Answer:We are motivated to prolong our good moods, and helping does that.
Step-by-step explanation:
When you feel good you always want it to last longer or forever if possible so you will do what ever else will keep you constantly happy just to maintain your good mood.
Amos for example is happy in school and in his relationship and ofcourse he would want to maintain that good mood and you know the relief and joy you feel after helping someone so to maintain his good mood he helps this pedestrian who has fallen down cause this would help him maintain his good mood.