The severe and fatal malaria is caused by

Options

A. Plasmodium vivax
B. Plasmodium ovale
C. Plasmodium malarriae
D. Plasmodium falciparum.

Answer

To answer the question "The severe and fatal malaria is caused by?", we need to analyze the options provided, which are different species of the Plasmodium genus. Here’s the step-by-step solution:

### Step 1: Identify the Options
The options given are:
1. Plasmodium vivax
2. Plasmodium ovale
3. Plasmodium malariae
4. Plasmodium falciparum

### Step 2: Understand Each Plasmodium Species
- **Plasmodium vivax**: Causes benign tertian malaria, characterized by fever occurring every second day. It is not considered severe or fatal.

- **Plasmodium ovale**: Similar to P. vivax, it also causes benign tertian malaria. It is not severe and can be treated effectively.

- **Plasmodium malariae**: Causes benign quartan malaria, with fever occurring every third day. This type is also less severe compared to others.

- **Plasmodium falciparum**: This species causes malignant tertian malaria, which is severe and can be fatal. It leads to a high level of parasitization of red blood cells (RBCs), causing significant destruction and intravascular hemolysis.

### Step 3: Conclusion
Based on the analysis:
- The severe and fatal malaria is caused by **Plasmodium falciparum**.

### Final Answer
**Plasmodium falciparum** is the correct answer.

---