How does horseradish peroxidase (HRP) contribute to creating the final colored sample? A. HRP is a protein that becomes colored when bound to an antibody associated with its epitope. B. HRP is an enzyme that catalyzes the conversion of a substrate to a colored product. C. HRP is a type of antibody that changes color when incubated overnight with buffer. D. HRP is a protein that reacts with antibodies to turn cells blue when blocking buffer is added.