Consider the following statements and select the option which correctly identifies true (T) and false (F) ones.
(i) Diatoms float in water due to the presence of light storage fats with silica.
(ii) AIDS virus kills WBC and reduces immunity of the body.
(iii) Escherichia coli is present in intestine of human where they help in digestion of food.
(iv) A virus always consists of double strands of DNA or RNA surrounded by protein coat.

Options

A. `{:("(i)","(ii)","(iii)","(iv)"),(T,F,T,F):}`
B. `{:("(i)","(ii)","(iii)","(iv)"),(T,T,T,F):}`
C. `{:("(i)","(ii)","(iii)","(iv)"),(T,T,F,F):}`
D. `{:("(i)","(ii)","(iii)","(iv)"),(T,F,T,T):}`

Explanation

To solve the question, we need to evaluate each of the four statements one by one to determine whether they are true (T) or false (F).

### Step-by-Step Solution:

1. **Statement (i): Diatoms float in water due to the presence of light storage fats with silica.**
- **Evaluation**: Diatoms are a type of algae that contain silica in their cell walls, which contributes to their buoyancy. They also have light storage fats that help them float. Therefore, this statement is **True (T)**.

2. **Statement (ii): AIDS virus kills WBC and reduces immunity of the body.**
- **Evaluation**: The AIDS virus, specifically the Human Immunodeficiency Virus (HIV), attacks and destroys white blood cells (WBCs), leading to a weakened immune system. This statement is also **True (T)**.

3. **Statement (iii): Escherichia coli is present in the intestine of humans where they help in digestion of food.**
- **Evaluation**: Escherichia coli (E. coli) is a beneficial bacterium found in the human intestine that aids in digestion and nutrient absorption. Thus, this statement is **True (T)**.

4. **Statement (iv): A virus always consists of double strands of DNA or RNA surrounded by a protein coat.**
- **Evaluation**: This statement is incorrect because viruses can contain either single-stranded or double-stranded DNA or RNA. Therefore, this statement is **False (F)**.

### Summary of Statements:
- (i) True (T)
- (ii) True (T)
- (iii) True (T)
- (iv) False (F)

### Final Answer:
The correct identification of the statements is:
- (i) T
- (ii) T
- (iii) T
- (iv) F