Question

the export of from the southern colonies was crucial to their economy.

Explanation:

The Southern Colonies (like Virginia, Maryland, etc.) had an agrarian economy reliant on cash crops. Key exports included tobacco, rice, indigo, or cotton (though cotton became more prominent later, tobacco/rice/indigo were early). Tobacco was a major cash crop for Virginia and Maryland, driving their economy via export to Europe.

Answer:

tobacco (or rice, indigo, cotton; tobacco is a primary example for early Southern Colonies)