In an Immunodiffusion Test to Diagnose Histoplasmosis,a Patient's Serum Is

Multiple Choice

In an immunodiffusion test to diagnose histoplasmosis,a patient's serum is placed in a well in an agar plate.In a positive test,a line forms as the serum diffuses from the well and meets material diffusing from a second well.What type of test is this?

A) an agglutination reaction
B) a precipitation reaction
C) a complement-fixation test
D) an indirect ELISA test
E) a direct ELISA test