Final answer:
Option a) increases contractility and decreases heart rate are cardiac physiological effects associated with the action of digoxin.
Step-by-step explanation:
The cardiac physiological effects associated with the action of digoxin include a) increased contractility and decreased heart rate.
Digoxin is a cardiac glycoside that inhibits the Na+/K+ ATPase pump, leading to increased intracellular calcium levels. This increased calcium concentration enhances the contraction of cardiac muscle, resulting in increased contractility. At the same time, digoxin also acts on the sinoatrial node to decrease the firing rate, thus reducing the heart rate.