This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S, Subject name: Pharmacology
Digoxin act on the heart by:(1994) 
Select and explain. 
A. Decreasing preload, B. Increasing the force of contraction, C. Decreasing the afterload, D. Decreasing heart rate
B: Increasing the force of contraction
Answer: B: Increasing the force of contraction 
Explanation: b.Ref: KDT, 5,h ed, p. 465, 457-458 & 4th ed, p. 494