A Neonate Is Suspected to Have Combined Immunodeficiency Disease (SCID)

A neonate is suspected to have combined immunodeficiency disease (SCID) . (One previous sibling died of this.) Which of the following would confirm the diagnosis?

A) Presence of the thymus but absence of the bursal equivalent
B) Deficiency in the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase system
C) Deficiency in adenosine deaminase, and loss of this enzyme activity
D) An absence of neutrophils