Final answer:
In the novel "Refugee," a powerful symbol for conflict on the M.S. St. Louis is a Nazi flag.
Step-by-step explanation:
In the novel "Refugee," a powerful symbol for conflict on the M.S. St. Louis is a Nazi flag. The MS St. Louis was a German ocean liner that carried Jewish refugees seeking refuge from Nazi-occupied Europe. The presence of a Nazi flag on the ship represents the persecution and oppression the passengers were fleeing from.