Suppose a researcher wants to measure difficulties for college students whose parents did not attend college. The researcher writes survey questions about grades, quality of support on campus; and financial resources, but does not ask about whether the student has family support or a good adviser. If the researcher has not tapped into all the dimensions of difficulties for first-generation college students, which of the following would be at risk?
a. concurrent validity
b. face validity
c. predictive validity
d. content validity