The correct answer is:
A) It bought several northern antislavery coalitions together.
In the early 1850s, Democrats fought the Whigs for political control. However, both struggled with an internal debate about slavery.
The Republican party, founded in the Northern states in 1854 by abolitionists, modernizers, ex-Whigs, and ex-Free Soilers, to prevent the spreading of slavery and promptly became the principal opposition to the dominant Democratic Party and the shortly popular Know Nothing Party.
By 1858, the Republicans dominated nearly all Northern states.