Answer:
B). Harun al-Rashid was a prominent ruler who expanded the cultural and intellectual growth of the Middle East.
Step-by-step explanation:
The key idea that 'Harun al-Rashid & One Thousand and One Nights' conveys is correctly displayed through the second option stating that 'Harun al-Rashid was an eminent ruler who made diligent efforts to expand the intellectual and cultural growth of the Middle East.' This statement is substantiated through the various developments made by Rashid and his reign being popularly known as the 'Islamic Golden Age.' Thus, option B is the correct answer.