**Core Concept**
Reteplase is a recombinant plasminogen activator used in the management of acute myocardial infarction (MI). It works by activating plasminogen to form plasmin, which breaks down fibrin clots and restores blood flow to the affected area.

**Why the Correct Answer is Right**
Reteplase is administered as a double-bolus injection, with the first dose given over 2 minutes and the second dose given 30 minutes later. This dosing regimen is based on the half-life of plasminogen activator inhibitor-1 (PAI-1), which is the primary inhibitor of plasminogen activators. The double-bolus regimen helps to maintain a therapeutic level of plasminogen activator activity while minimizing the risk of bleeding.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the dose of reteplase is not specified in milligrams per kilogram of body weight. Reteplase is typically administered as a fixed dose, regardless of patient weight.
**Option B:** This option is incorrect because the dose of reteplase is not 10 mg per hour. The recommended dose of reteplase is a double-bolus injection, not a continuous infusion.
**Option C:** This option is incorrect because the dose of reteplase is not 50 mg per hour. The recommended dose of reteplase is a fixed dose, not a variable dose based on patient weight or time.

**Clinical Pearl / High-Yield Fact**
When administering reteplase for acute MI, it's essential to monitor the patient for signs of bleeding, such as hematuria, hematemesis, or petechiae. Reteplase can increase the risk of bleeding, particularly in patients with a history of gastrointestinal bleeding or those taking anticoagulant medications.

**Correct Answer:** B. 10 units (not mg) over 2 minutes, followed by 10 units over 30 minutes