All of the following factors affect an area s biodiversity except
a. area.
b. number of endangered species.
c. climate.
d. diversity of niches.

All of the options enlisted here (area, climate, diversity of niches) affect an area's biodiversity except number of endangered species. That in no way affects an area's biodiversity, whereas the other options certainly do. 

Generally travels west to east but often shifts to north and south