D. Allowing Texas into the Union would upset the balance of slave and free states in Congress. Though it soon became a state since Manifest Destiny was a very popular idea at the time.
Christianity is the most widely practiced religion in the world, with more than 2 billion followers. The Christian faith centers on belief regarding the birth, life, and resurrection of Jesus Christ.
The *Red Scare* was a wholly unjustified political ploy that crippled the ability of the USA to deal with the USSR in a forthright manner so no it was not justified in the least.
D, the key word there is unsure which is a synonym for undecided. Hope this helps