Read the given statements carefully.
(i) Innate immunity is a specific type of defence, that is present at the time of birth.
(ii) Malignant malaria is caused by Plasmodium falciparum.
(iii) Malaria could be confirmed by Widal test.
(iv) Active immunity is slow and takes time to give its full effective response.
(v) Saliva in the mouth acts as physiological barrier for pathogens.
Which of the above statements are correct ?

Options

A. (ii), (iv) and (v)
B. (i) and (iii)
C. (i) and (v)
D. (ii), (iii) and (v)

Explanation

To determine which of the given statements are correct, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Statement (i)**: "Innate immunity is a specific type of defence, that is present at the time of birth."
- **Analysis**: Innate immunity is a non-specific defense mechanism that is present at birth. It includes physical barriers (like skin) and immune responses that do not target specific pathogens. Therefore, this statement is **incorrect**.

2. **Statement (ii)**: "Malignant malaria is caused by Plasmodium falciparum."
- **Analysis**: This statement is true. Plasmodium falciparum is known to cause the most severe form of malaria, often referred to as malignant malaria. Therefore, this statement is **correct**.

3. **Statement (iii)**: "Malaria could be confirmed by Widal test."
- **Analysis**: The Widal test is used to diagnose typhoid fever, not malaria. Malaria is typically diagnosed through blood tests that detect the presence of the Plasmodium parasite. Therefore, this statement is **incorrect**.

4. **Statement (iv)**: "Active immunity is slow and takes time to give its full effective response."
- **Analysis**: This statement is true. Active immunity develops over time as the immune system responds to an antigen, and it can take days to weeks to provide a full response. Therefore, this statement is **correct**.

5. **Statement (v)**: "Saliva in the mouth acts as a physiological barrier for pathogens."
- **Analysis**: Saliva contains enzymes and has an acidic pH that can inhibit the growth of bacteria, acting as a barrier against pathogens. Therefore, this statement is **correct**.

### Conclusion:
The correct statements are:
- Statement (ii): Malignant malaria is caused by Plasmodium falciparum.
- Statement (iv): Active immunity is slow and takes time to give its full effective response.
- Statement (v): Saliva in the mouth acts as a physiological barrier for pathogens.

Thus, the correct options are **2nd, 4th, and 5th**.