Final answer:
Income from the oil industry has most substantially impacted life in Southwest Asia, dominating the region's economic interactions with the global community and significantly shaping its economic landscape.
Step-by-step explanation:
The income from the oil industry has affected life the most in Southwest Asia. The provision and export of oil have dominated economic activity in relation to the global community, particularly in countries like Saudi Arabia, which have ample petroleum reserves.
The wealth garnered from oil sales to other countries has notably influenced the economic landscape of Southwest Asia. This reliance on a non-renewable resource suggests that once the oil reserves are depleted, these countries may need to diversify their economic activities to maintain national income.