In the Homogeneous Assay for Methamphetamine, the Kit Comes with Methamphetamine

In the homogeneous assay for methamphetamine, the kit comes with methamphetamine linked to glucose-6-phosphate dehydrogenase, and antibody to the drug blocks the action of the enzyme when the patient's serum contains

A) low levels of the drug and there is less enzyme reactivity than without the patients serum
B) high levels of the drug and there is less enzyme reactivity than without the patient's serum
C) the drug and there is more enzyme reactivity
D) the drug and there is less enzyme reactivity