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: Pharmacology
A drug following first order kinetics is being administered by constant i.v. infusion at a rate of 10 mg/min. Its steady state plasma concentration is 2 mg/min. If the dose rate is increased to 20 mg/dl, what will be the new steady state plasma concentration ? 
Select and explain. 
A. 6 mg/dl, B. 4 mg/dl, C. 3 mg/dl, D. 1 mg/dl
B: 4 mg/dl
Answer: B: 4 mg/dl 
Explanation: None