What Prevented White Southerners from Working to Diversify Their Economy

What prevented white southerners from working to diversify their economy in the nineteenth century?

A) Southerners did not want to exploit white workers economically.
B) Wealthy southern investors believed agricultural labor was more virtuous than industrial labor.
C) Southerners resisted railroad construction because they believed it would divide large landholdings.
D) Wealthy planters believed that the plantation economy would continue to produce wealth indefinitely.