Why would the admission all lands gained by the Mexican Cession as free states alarm Southerners? A. It would overturn the Northwest Ordinance.
B It would not follow the proposed Wilmont Proviso.
C It could upset the balance of power between free and slave states.
D It would make Texas a free state.

option d is correct. corroborated sources of historical evidence   is necessary to validate a claim about an event in history.

historians tend to use written sources, but audio and visual materials as well as artifacts are important objects that supply information to modern historians.

historical sources are usually divided into two categories: primary and secondary sources. depending on the historian's intent, some sources shift their designation. determining what type of sources toimplement, and the level of credibility and reliability of those sources, is a significant step in critical thinking for the historian.

explanation:

sorry its a lil late, but the answer is d. the rotation 180° about z'