Determine the Effects of a New High Carbohydrate Diet Intended

Multiple Choice

determine the effects of a new high carbohydrate diet intended to treat Depression of prisoners at maximum security prisons, a researcher conducts a study. Five hundred inmates at the Burlington Maximum Security Penitentiary are selected
To participate in the study. The researcher puts the 400 inmates not in solitary Confinement on the new diet. The 100 inmates in solitary confinement are given their Regular meals. The 400 inmates on the new diet are not aware that they being Studied or that their diet has been modified, but have many fewer reported cases of
Depression after 30 days.
-Refer to the situation described above ; how large was the sample?

A) 30
B) 100
C) 400
D) 500
E) None of the above.