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
CAP in Lac operon is an example of: 
Select and explain. 
A. Positive regulator, B. Negative regulator, C. Constitutive expression, D. Attenuation
A: Positive regulator
Answer: A: Positive regulator 
Explanation: A i.e. Positive regulator