The statement that best evaluates how geography affects diversity within political parties and political outcomes is: "States such as Kansas, Nebraska, North Dakota, Oklahoma, South Dakota, and Texas tend to be strongly Republican, limiting diversity."
This statement correctly identifies geographical areas that are predominantly Republican, which can lead to a lack of political diversity within those states. In contrast, other states mentioned in the other statements are either not accurately described as strongly Republican or are actually known for their political diversity or Democratic leanings, such as California and New York. Thus, the geographical distribution of political party strength can significantly influence the diversity of political opinions and outcomes in those regions.