Answer:
Out of the given options, religious affiliation is the main unifying factor for most people living in southwest Asia.
Explanation:
- All the countries of the middle east or southwest Asia are predominantly Muslim countries with the worlds highest concentration of Muslim population.
- In all the countries of the middle east, Islam is the official religion of the states and is backed and promoted by the governments.
- In countries like Saudi Arabia, it is mandatory for an individual to be Muslim to officially be a citizen of Saudi Arabia.