What is the main difference between fluorochrome staining (e.g., auraminerhodamine screening for Mycobacterium tuberculosis) and indirect fluorescent antibody (IFA) staining?

A) Fluorochromes are more specific and used just for Mycobacterium tuberculosis.
B) IFAs are less specific since they use antibody to a different species' antibody (i.e., rabbit antibody to human antibody).
C) Fluorochrome staining is less sensitive than comparable staining with light microscopy.
D) IFA's specificity is dependent on the primary antibody used; fluorochromes lack the antibody specificity.