A Sociologist Studying American Neighborhoods Identifies a Causal Effect of Income

Multiple Choice

A sociologist studying American neighborhoods identifies a causal effect of income on the availability of healthy and nutritious foods.Specifically,people with lower incomes tend to live in neighborhoods where there are more fast food restaurants and less access to fresh fruits and vegetables.Given this finding,the researcher can be confident in concluding that the study has

A) face validity.
B) a reliable measure.
C) internal validity.
D) external validity.