Could someone please help me with these questions about Manifest Destiny I beg

Okay: 1: Manifest Destiny was the belief by many Americans that it was God’s Will that they spread the continent and teach their culture,religion, etc.
2: The impact of Manifest Destiny led to the US trying to expand west, this would lead to the Mexican-American War and Mexican Cession.
3: it was more of a good thing for the US, if they expanded west, they have both borders, they have more resources, and they would have more land for slavery to spread.
4: I guess that’s your opinion
5: 2 pros: Allows the US to secure their borders, Allows the US to gain more territory and gain the resources, Cons: It led to many Native Americans being killed and their land being took, it further led to sectionalism in the US. It’s impacts would eventually lead to a war between Mexico and the US, it also further divides the US because Polk, wanted the land for slavery to spread however many US people did not want that to happen.

The answer is option a. boundary line drawn by pope alexander iv in 1493.