**Core Concept:** The half-life of a substance is the time it takes for the concentration of the substance to decrease by half after administration. In the context of this question, we are discussing the half-life of alteplase, which is a recombinant tissue plasminogen activator (tPA) used as a thrombolytic agent in acute ischemic stroke treatment.

**Why the Correct Answer is Right:** The correct answer, **D** (3.5 hours), represents the half-life of alteplase, a thrombolytic agent used to dissolve blood clots in acute ischemic stroke treatment. The half-life of a drug is determined by its pharmacokinetic properties, such as clearance, volume of distribution, and protein binding. Alteplase has a moderate plasma protein binding (approximately 20%), low clearance, and a large volume of distribution. These pharmacokinetic features contribute to the relatively long half-life of alteplase, making it suitable for its intended therapeutic purpose.

**Why Each Wrong Option is Incorrect:**

A. 10 minutes: This value is too short, indicating a high clearance and/or high protein binding, which is not the case for alteplase.
B. 12 hours: This value is too long, suggesting a low clearance and/or low protein binding, which is not the case for alteplase.
C. 2 hours: This value is also too long, similar to option B, and not representative of alteplase's pharmacokinetic properties.

**Clinical Pearl / High-Yield Fact:** The half-life of alteplase is crucial for its therapeutic efficacy in acute ischemic stroke treatment. A longer half-life allows for a single dose administration, reducing the risk of bleeding complications associated with multiple injections. Additionally, a longer half-life ensures that the drug remains effective over a significant portion of the ischemic penumbra (penetrating tissue at risk of infarction due to an ischemic stroke).