Demography is the study of: A. behavior and migration patterns. B. changes in beliefs. C. human population characteristics. D. marketing and buying habits.

## Step 1<br />Demography is a branch of sociology that focuses on the study of human populations. This includes the analysis of the size, structure, and distribution of these populations, and spatial or temporal changes in them in response to birth, migration, aging, and death.<br />## Step 2<br />Given the options, we need to identify which one best describes the study of demography.<br />## Step 3<br />Option A, "behavior and migration patterns", while related to demography, is not the primary focus of the study.<br />## Step 4<br />Option B, "changes in beliefs", is more related to psychology or sociology, not demography.<br />## Step 5<br />Option D, "marketing and buying habits", is more related to marketing or consumer behavior, not demography.<br />## Step 6<br />Option C, "human population characteristics", is the most accurate description of what demography studies. It includes the size, structure, and distribution of human populations, and changes in these over time due to birth, migration, aging, and death.