The correct answer is D) Tobacco.
The resource that helped promote the economic growth of the Southern colonies was tobacco.
To put it in simple terms, Tobacco was the king of crops in the Jamestown, Virginia colony that was founded in 1607.
John Rolfe had brought some tobacco seeds from the Caribbean Islands of Trinidad y Tobago, and seed them in the fertile lands of Virginia. This resulted in a major success. This tobacco leaf was grayer and tasted bitter than the European tobacco.
So this American tobacco was exported to the European markets that seemed to demand more.