Concept:The parable that mainly teaches God’s forgiveness is the parable of the prodigal son.Explanation:The prodigal son wasted his inheritance, but when he returned home, his father forgave him and welcomed him back with joy.This illustrates repentance and forgiveness.The other parables teach different lessons: the unjust steward is about shrewdness, the rich fool about greed, and the good Samaritan about showing mercy to others.Answer:D. prodigal son