Which headline does not belong?

Question

A. “Missouri Compromise Allows Two New States into the Union”
B. “Congress Agrees to Compromise of 1850”
C. "The Northwest Ordinance Outlines Process for Statehood"
D. “Popular Sovereignty Adopted Under Kansas- Nebraska Act”

Answer 1

C. "The Northwest Ordinance Outlines Process for Statehood" (This headline is about a different historical event unrelated to compromises allowing states to enter the Union.)