I want to know the answer to the following question:
What nation lost the Battle of Yarmouk?
All the background I'm provided with is that "However many early history books like the Islamic Conquest of Syria Fatuhusham by al-Imam al-Waqidi state that after the conversion to Islam Muawiyah's father Abu Sufyan ibn Harb and his brothers Yazid ibn Abi Sufyan were appointed as commanders in the Muslim armies by Muhammad.". Is that enough to answer the question?
Answer: no