I need detailed explanation. thank you so much.

7. What is the opportunity cost of one more Xylophone in Country B? A) 5 Xylophones B) 1/5 Xylophones C) 5 Yogurt D) 1/5 Yogurt E) None of the above. 8. Country A has an comparative advantage in the production of A) both goods. B) Xylophones only. C) Neither good. D) Yogurt only. 9. What is an acceptable terms of trade where both countries can gain from trade? A) 4 Yogurt for 1 Xylophone B) . Yogurt for 1 Xylophone C) 4 Xylophones for | Yogurt D) 1/3 Xylophones for 1 Yogurt 10. With specialization and trade what will be the production in each country? A) Country A will produce 270 units of Xylophones and Country B will produce 1650 units of Yogurt. B) Country A will produce 810 units of Yogurt and Country B will produce 330 units of Xylophones. C) Country A will produce 202.5 units of Xylophones and Country B will produce 1320 units of Yogurt. D) Country A will produce 1080 units of Yogurt and Country B will produce 412.5 units of Xylophones