Southern whites, including small merchants, small landowners, and former whigs, where attracted by republican policies of:

White Southerns where attracted by republican policies of civil rights and racism.

While Democrats were dominant in the south before the 1960's and Republicans were dominants in the north, The civil rights movement created racial tension in the South, so Republican candidates such as Senator Barry Goldwater (First republican to win the south in 1964) and President Richard Nixon (who won the south in his reelection) created the Southern Strategy.

The Southern Strategy consisted in realigning the White Southern Democrats to the Republican Party mostly by "dog whistle politics" (who referred to appealing to the issues that appeal to a racist rather than declaring themselves racist). They also adopted the language of states' rights and in doing so the Southern Strategy Civil Rights Protesters in the same place as feminists, environmental activists and other leftists who were challenging the status quo.

Most of the South remains dominated by Republicans nowadays.

B: Encouraging new industries.

Explanation:

Southern whites, including small merchants, small landowners, and former Whigs, were attracted by Republican policies of Encouraging new Industries.