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: Biochemistry
The minimum level of TSH that can he detected by TSH assay of the third generation thyroid function tests is which of the following? 
Select and explain. 
A. 0.4 lU/ml, B. 0.04 IU/ml, C. 0.004 lU/ml, D. 4 IU/ml
B: 0.04 IU/ml
Answer: B: 0.04 IU/ml 
Explanation: Functional sensitivities for three generations of TSH assays: First generation: Functional sensitivity is 1-2 IU/mL Second generation: Functional sensitivity is 0.1-0.2 IU/mL Third generation: Functional sensitivity is 0.01-0.02 IU/mL Among the options more appropriate is 0.04 IU/mL Ref: Aicle: Evolution of TSH Assays: A Third Generation Viewpoint