Which of the following is a commonly prescribed beta blocker?

Atenolol is a commonly prescribed beta blocker that works by blocking the effects of adrenaline on the heart and blood vessels, leading to a decrease in heart rate and blood pressure. This makes it effective in treating conditions such as hypertension, angina, and heart rhythm disorders. As a selective beta-1 adrenergic antagonist, atenolol primarily affects the heart rather than other organs, which helps in managing cardiovascular issues with a lower risk of certain side effects associated with non-selective beta blockers.

In contrast, the other options include medications that have different mechanisms of action and uses. Captopril is an ACE inhibitor used primarily for hypertension and heart failure. Naproxen and ibuprofen are nonsteroidal anti-inflammatory drugs (NSAIDs) utilized for pain relief and to reduce inflammation, with no beta-blocking properties. Thus, atenolol stands out as the only medication in the list that serves the specific role of a beta blocker.