**Core Concept**
The radical treatment of malaria involves targeting the liver stages of the parasite to prevent relapse. **Primaquine** is a key drug used for this purpose, especially against **Plasmodium vivax** and **Plasmodium ovale**. It is known for its ability to clear dormant hypnozoites from the liver.

**Why the Correct Answer is Right**
Primaquine is typically given in a dosage of 15-30 mg per day for 14 days for the radical cure of malaria. This dosage is crucial for ensuring that the liver stages of the parasite are adequately targeted and eliminated, thus preventing future relapses. The exact mechanism involves the generation of reactive oxygen species that damage the parasite's cellular components.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the dosage is too low to effectively target the liver stages of the parasite.
**Option B:** This option might seem plausible but does not align with the standard recommended dosage for radical treatment.
**Option D:** This option is incorrect as it exceeds the typical recommended dosage, potentially increasing the risk of side effects without adding therapeutic benefit.

**Clinical Pearl / High-Yield Fact**
A crucial point to remember is that primaquine can cause **hemolysis** in individuals with **glucose-6-phosphate dehydrogenase (G6PD) deficiency**, making it essential to screen for G6PD deficiency before initiating treatment.

**Correct Answer:** Correct Answer: D. 15 mg/day for 14 days