**Core Concept**
Digoxin is a cardiac glycoside used to treat atrial fibrillation, atrial flutter, and heart failure. It works by inhibiting the Na+/K+ ATPase pump, leading to an increase in intracellular calcium and a subsequent increase in contractility.

**Why the Correct Answer is Right**
Digoxin is contraindicated in patients with a history of hypersensitivity to digoxin or other cardiac glycosides. This is because cross-reactivity can occur, leading to severe allergic reactions. Additionally, digoxin is also contraindicated in patients with hyperkalemia, as it can further increase potassium levels, leading to cardiac arrest.

**Why Each Wrong Option is Incorrect**
**Option A:** Wolff-Parkinson-White (WPW) syndrome is not a contraindication for digoxin, but rather a condition that requires careful monitoring due to the risk of inducing antegrade conduction down the accessory pathway.
**Option B:** Congestive heart failure (CHF) is actually an indication for digoxin, as it can improve symptoms and increase exercise tolerance.
**Option C:** Hypokalemia is not a contraindication for digoxin, but rather a condition that requires careful monitoring and supplementation with potassium, as digoxin can exacerbate hypokalemia.

**Clinical Pearl / High-Yield Fact**
Digoxin toxicity can be remembered using the mnemonic "Dyshrythmias, Nausea, Vomiting, Confusion, and Visual Disturbances," which represents the classic symptoms of digoxin toxicity.

**Correct Answer: D. Patients with a history of hypersensitivity to digoxin or other cardiac glycosides.**