A small amount of antigen is injected under the skin of a patient. After 30 minutes there is no apparent change at the injection site, but 36 hours later the patient reports that the area is red and swollen. This type of response is due to
A) type I hypersensitivity. B) type II hypersensitivity. C) type III hypersensitivity. D) type IV hypersensitivity. E) immunodeficiency.