I loved this one, it was C. You can't separate and be friends. Cast down your buckets where you are means cast out yourself as a friend. Show them you can be friendly and they will accept you. That's why C is the correct answer, I've also done this one before.
I would say religious and racial discrimination.
Ruth followed either her sister- in- law I think and became a descendent of Jesus. Christ. Both their husbands died and had to go back to their family homes. Ruth instead followed her sister-in- law.