Answer:
The percent of all voters that are registered Democrats is part of the marginal distribution of political party - Answer B.
Explanation:
Marginal distribution is the probability function or description of a subset of variables from a particular sample data. It is created or described when, in a sample we have a specific categorization odf our data. When we take into account both subsets simultaneously we talk of a joint distribution.
In your table there are two subsets or categories. Gender and political party. The question only talks about the democrats, one value of the sepcific category of political parties., so its not a joint distribution. As we are talking only of political parties , withput considering gender of democrats, the marginal distribution to consider is the one of political parties