In an Immunodiffusion Test to Diagnose the Fungal Disease Histoplasmosis,a

Multiple Choice

In an immunodiffusion test to diagnose the fungal disease histoplasmosis,a patient's serum is placed in a well in an agar plate.In a positive test,a precipitate forms as the serum diffuses from the well and meets material diffusing from a second well.In this test process,what is the most likely identity of the material in the second well?

A) antibodies
B) a purified fungal antigen
C) entire fungal cells
D) a purified protozoan antigen
E) red blood cells