Okay, let's tackle this question. The user wants me to explain the correct answer for the question "Malarial parasite was discovered by -" with the correct answer being Charles Louis Alphonse Laveran. First, I need to recall who discovered the malarial parasite. I remember that Laveran was a French physician who made this discovery in the 19th century. He was awarded the Nobel Prize for this work.

The core concept here is the history of medical discoveries, specifically related to malaria. The question is testing knowledge of key figures in the history of parasitology. The correct answer is Laveran, but I need to make sure the explanation is accurate.

Next, the explanation for why Laveran is correct: He discovered Plasmodium in the blood of malaria patients in 1880. This was a significant breakthrough because it identified the causative agent of malaria. I should mention the year and the method he used, like examining blood smears under a microscope.

Now, the wrong options. The other options might include names like Ronald Ross, who discovered that mosquitoes transmit malaria, or maybe someone else like Louis Pasteur. I need to clarify that Ross's work was about transmission, not the discovery of the parasite itself. Also, maybe mention that Laveran's discovery was in humans, while others might have worked on different aspects.

The clinical pearl here is to remember Laveran for the discovery of the parasite and Ross for the transmission mechanism. Mnemonics could help here, like linking L for Laveran and L for the parasite (Plasmodium). Also, noting the Nobel Prize adds to the high-yield fact.

I need to structure the explanation according to the user's guidelines. Make sure each section is concise and covers all the necessary points without exceeding the character limit. Check that all sections are included: Core Concept, Why Correct, Why Wrong, Clinical Pearl, and Correct Answer Line. Use bold for key terms and keep the language clear for postgraduate students.

**Core Concept**
The discovery of the malarial parasite involves identifying the causative agent of malaria. This question tests knowledge of historical milestones in parasitology and the scientists who linked specific pathogens to diseases.

**Why the Correct Answer is Right**
Charles Louis Alphonse Laveran discovered the malarial parasite (*Plasmodium* spp.) in 1880 by observing it in the blood of malaria patients using a microscope. His work established the parasitic origin of malaria, earning him the 1907 Nobel Prize in Physiology or Medicine. This discovery was pivotal in understanding malaria’s pathogenesis and guiding future treatments.

**Why Each Wrong Option is Incorrect**
**Option A:** Ronald Ross identified the mosquito as the vector for malaria transmission in 1897, not the parasite itself.
**Option B:** Louis Pasteur is renowned for germ theory and vaccines, not malaria.
**Option C:** Robert Koch discovered the tuberculosis and cholera bacteria but not the malarial parasite.

**Clinical Pearl**
Remember *L* for Laveran (parasite discovery) and *R* for Ross (mosquito transmission). Both were Nobel laureates, but their contributions to malaria differ: Laveran identified the *Plasmodium* parasite, while Ross elucidated its transmission cycle.

**Correct Answer

✓ Correct Answer: C. Laveran