Malaria which is most serious and fatal is caused by

Options

A. Plasmodium vivax
B. P.ovale
C. P. malariae
D. P. falciparum

Answer

To answer the question "Malaria which is most serious and fatal is caused by," we will analyze the options provided and determine which species of Plasmodium is responsible for the most severe form of malaria.

### Step-by-Step Solution:

1. **Identify the Options**: The question provides four options:
- A) Plasmodium vivax
- B) Plasmodium ovale
- C) Plasmodium malaria
- D) Plasmodium falciparum

2. **Understand Each Species**:
- **Plasmodium vivax**: Causes benign tertian malaria, has an incubation period of 14 days. It is serious but not the most fatal.
- **Plasmodium ovale**: Causes mild tertian malaria, also with an incubation period of 14 days. This form is milder than that caused by P. vivax.
- **Plasmodium malaria**: Causes quartan malaria, with a longer incubation period of 27 to 30 days. It can be serious but is not the most fatal.
- **Plasmodium falciparum**: Causes deadly cerebral malaria, with the shortest incubation period of 10 to 12 days. This form is known to be the most serious and fatal.

3. **Determine the Most Serious and Fatal Species**: Based on the descriptions:
- Plasmodium falciparum is recognized as the most serious and fatal form of malaria, leading to severe complications and a higher mortality rate.

4. **Conclusion**: Therefore, the answer to the question is:
- **Plasmodium falciparum** (Option D) is the causative agent of the most serious and fatal form of malaria.

### Final Answer:
- **Plasmodium falciparum**