Describe how the US expanded its economic and political influence in the late 1800s.

Expansion (1820-1849) During the early 1800's, settlers moved westward over the Appalachian Mountains into the new states and territories. The build-up of the West gave rise to changes in American politics. As areas in the West gained large populations, they were admitted to the Union as states.

The correct answer is a

Ifound the exercise on the internet. attached is the list mentioned above.in order for a compound to be considered optically active it can't have any axis or plan of symmetry. the molecule  shouldn't also  be superimposable on its mirror image.with such considerations, the compounds that are optically active are: -third compound on the first image is optically active; -second and third compound from the second image are optically actives.