Lelani Wants to Know What Percentage of All American College

Lelani wants to know what percentage of all American college students receive financial aid their freshman year. She attends a two-year community college, to which many students commute to campus every day. She stands outside the dining hall one weekday evening and hands out surveys to every third person entering the hall for dinner. Her data will

A) not be generalizable to all American college students, because she did not use a representative sample.
B) be completely invalid, because evenings are never a good time to do research.
C) be valid and generalizable, because she used random sampling and a representative sample.
D) be valid and generalizable as long as she continues to stand there; her presence will compel people to return the surveys to her.