## **Core Concept**
The patient's symptoms of palpitations after consuming a large amount of coffee suggest a likely diagnosis of caffeine-induced tachycardia or arrhythmia. Caffeine acts as a stimulant to the heart, increasing heart rate and contractility by blocking adenosine receptors and increasing the release of catecholamines.

## **Why the Correct Answer is Right**
The correct answer, **D. Metoprolol**, is appropriate for managing symptoms of palpitations, especially when they are believed to be caused by excessive catecholamine activity, such as that induced by caffeine. Metoprolol, a beta-1 selective (cardioselective) beta-blocker, can effectively reduce heart rate and alleviate symptoms of palpitations by blocking the effects of catecholamines on the heart. This approach addresses the immediate need to control the heart rate without necessarily addressing the underlying cause (caffeine consumption), which can be managed supportively.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is not provided, but typically, treatments not directly addressing the acute management of tachycardia or palpitations would be incorrect in this context.
- **Option B:** This option is not provided, but generally, treatments that do not directly manage the symptoms or are not appropriate for acute management would be incorrect.
- **Option C:** This option is not provided, but similar to options A and B, if it does not offer a direct and immediate management strategy for the symptoms presented, it would be considered incorrect.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that beta-blockers like metoprolol are effective for managing symptoms of palpitations caused by increased sympathetic activity, such as that seen with caffeine consumption. However, it's also crucial to advise the patient to avoid excessive caffeine intake in the future to prevent recurrence.

## **Correct Answer:** D. Metoprolol