Why did Alexander's empire stop when and where it did? A
He had conquered all of the lands that he wanted.

B
He could not cross the mountains of Asia.

C
His soldiers were war-weary and wanted to go home.

no statements but ok.

the statement that best describes the idea of manifest destiny that was used in the 19th century would be that "it was fate that the united states would continue to  expand westward," since people thought the us was "destined" to do so. 

there are many ways of getting involved on your local party. attached you will find the brochure that describes some ideas: go ahead and visit your local hq, become a volunteer on your comnunity or struggle up for your own ideas so you can make them real.