Please help, this is about he civil war but also reading !!

Read the paragraph from the section "Peace, Order, Tranquility, And Civil Authority Now Exist." These waves of newly arrived white Southerners would clash head-on with another growing population in the state: formerly enslaved people. Texas's black population had also exploded during the Civil War since many Southern planters brought their slaves there to avoid them being captured by the Union Army. "Of course there's going to be blowback against the emancipation of slaves," Grear says. There was violence against newly freed slaves throughout Texas. Which words from the paragraph MOST help the reader understand what is meant by "blowback" in this excerpt?

(A) waves; population
(B) exploded; slaves
(C) head-on; emancipation
(D) clash; violence​