Item 4 Refer to the article "Harun al-Rashid & One Thousand and One Nights." Which two details support the central idea that Harun al-Rashid was an extremely rich and learned ruler? "Libraries sprouted in cities across the caliphate, including the wonderfully named House of Wisdom in Baghdad, which al-Rashid helped found." "…during al-Rashid's rule, the Islamic world began to experience an explosion of cultural and intellectual growth." "…al-Rashid was the second son of his father, al-Mahdi, an important political leader." "…al-Rashid became the caliph -- or ruler -- of an Islamic state whose capital was the city of Baghdad."