Question

Which of the following most directly contributed to the spread of the Muslim faith in the Islamic Empire?

the founding of the House of Wisdom

the levying of the jizya

the construction of Baghdad as the capital city

the publishing of One Thousand and One Nights

Answer 1

I'd probably go with the second choice -- the levying of the jizya, or the tax on non-Muslims.

This was a source of revenue for Islamic empires such as the Umayyad and the Abbasid caliphates. However, a number of converts simply switched faiths in order to get out of paying the tax and it became something of a problem when there were fewer people paying it.

The other choices don't work. The founding of the House of Wisdom did not contribute to the spread of Islam, though it helped preserve a large number of ancient writings. Moving the capital to Baghdad was meant to appease those who were concerned over Arab influence in the new regime (which was a problem with the Umayyads). Publishing the 1001 Nights also didn't spread Islam, though it shared a number of great stories with the rest of the world (it's where Aladdin's story comes from).