This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
Rapid serological diagnostic tests include all except? 
Select and explain. 
A. Latex agglutination, B. Spectrophotometry, C. Gel electrophoresis, D. Radioimmunoassay
B: Spectrophotometry
Answer: B: Spectrophotometry 
Explanation: Ans. is 'b' i.e., Spectrophotometry