Final answer:
The Euphrates River helped establish direct trade between the people of the Fertile Crescent and Asia Minor, as it is the longest river flowing from Turkey through Syria into Iraq.
Step-by-step explanation:
The Fertile Crescent is a region in the Middle East which is renowned for its rich soil and early civilization developments between the Tigris and Euphrates Rivers. When considering which river helped establish direct trade between the people of the Fertile Crescent and Asia Minor, we should take into account the courses of these rivers.
As both the Tigris and Euphrates Rivers originate in Turkey, they would have provided routes for trade and interaction between the peoples in the Fertile Crescent and those in Asia Minor. The Euphrates River specifically is noted to be the longest river in Southwest Asia and flows from Turkey through Syria and into Iraq, which would make it the most strategic and direct route for trade with Asia Minor. Therefore, the answer is D) the Euphrates River.