This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Pharmacology
Therapeutic plasma level of the digoxin is 
Select and explain. 
A. 0.1-0.3 ng/ml, B. 0.8-1.5 ng/ml, C. 1.2-2 ng/ml, D. More than 2.4 ng/ml
B: 0.8-1.5 ng/ml
Answer: B: 0.8-1.5 ng/ml 
Explanation: Ref-KDT 6/e p497 Digitoxin digoxin Therapeutic plasma concentration 15-30ng/ml 0.5-1.4 ng/ml Toxic plasma concentraton >35 ng/ml >2.5 ng/ml