Answer:
A. The cash-crop empire of the South could expand and boost the economy.
Step-by-step explanation:
Expansion to the westward was a way of boosting the economy and making the national territory bigger. With this expansion, many settlers settled in the newly created states and started productive crops, housing and factories that boosted the American economy and promoted wealth for the country.
As a result, the country began to expose more and import less, which is one of the major factors that elevated the USA to a position of economic power.