In the early 1850s, with the wes

In the early 1850s, with the westward movement, the slavery issue became a serious political issue endangering the unity of the country because ___.
A、whether the future states formed as aresult of the west ward movement should be free or slave world affect the balance of power in the Senate
B、the southin sisted that slavery should beallowed tospread into all new territories
C、the north refused to let slavery spread into new territories
D、the north want edtoput and end to slavery
【正确答案】：A
【题目解析】：在19世纪50年代早期，随着西部运动，奴隶制问题成为一个严重的政治问题，威胁到国家的统一，因为不管未来的州是作为西部运动的结果而形成应该是自由的还是奴隶的世界，都会影响参议院的权力平衡。