Final answer:
Propranolol is a non-selective beta-blocker that blocks both beta1 and beta2 receptors, reducing heart rate and blood pressure, and affecting smooth muscle relaxation. This makes 'd. Both A and C are correct' the right answer.
Step-by-step explanation:
The expected pharmacological action of propranolol is to block the stimulation of beta1 (β1) and beta2 (β2) receptors. Propranolol is a non-selective beta-blocker, which means it binds to both β1- and β2-adrenergic receptors. By doing so, it inhibits the effects of adrenaline (epinephrine), leading to a decrease in heart rate and blood pressure, and it can also cause the relaxation of smooth muscle in the airways. The blocking of β1-receptors primarily affects the heart, reducing cardiac workload and oxygen demand, while the blocking of β2-receptors can lead to bronchoconstriction, which is why caution is advised in asthmatic patients. Therefore, the correct answer to the question is 'd. Both A and C are correct.'