Along with the question the correct answer is option C, Democratic.
Northern and southern farmers supports whom?
Northern immigrants and southern farmers overwhelmingly supported the Democratic Party. Northern Democrats generally welcomed and welcomed immigrants into their party.
Because each party's supporters included both Northerners and Southerners, each party devised its own compromises on the slavery issue in order to satisfy all of its members.
Initially, it was other factors, primarily industrialization and immigration, that threw the balance off.