Answer:
B) an immunochromatographic assay
Step-by-step explanation:
An immunochromatographic assay is a rapid chromatographic immunoassay for the qualitative detection of human chorionic gonadotropin hormone in urine or serum to aid in the early detection of pregnancy.
These pregnancy tests are specifically desgined for professional users for determination of early pregnancy,but have also found a place in home pregnancy testing applications due to ease of use and low cost. The specificity is 98% meaning that test is highly selective for hCG glycoprotien.
Hence B) an immunochromatographic assay is the right answer.