In the Study Where Subjects with High and Low Stress

In the study where subjects with high and low stress received nasal drops containing the common cold virus, results indicated

A) no consistent relationship between catching a cold and stress level.
B) both groups were likely to develop a cold.
C) subjects in the high stress group were much more likely to catch a cold than those in the low stress group.
D) placebos were able to produce cold symptoms.