Given below are some food items
1. Boiled and mashed potato
2. Boiled and charred rice
3. A slice of bread
4. Sugar solution
5. Coconut oil
Which of the above will give blue-black colour when tested with iodine solution?

Options

A. 1, 2 and 3
B. 1, 3 and 5
C. 1 and 3
D. 2 and 4

Explanation

To determine which of the food items will give a blue-black color when tested with iodine solution, we need to analyze each item based on its starch content. The blue-black color indicates the presence of starch when iodine solution is added.

### Step-by-Step Solution:

1. **Identify the food items**: We have the following food items:
- Boiled and mashed potato
- Boiled and charred rice
- A slice of bread
- Sugar solution
- Coconut oil

2. **Understand the iodine test**: The iodine test is used to detect the presence of starch. When iodine solution (iodine dissolved in potassium iodide) is added to a substance containing starch, it turns blue-black.

3. **Analyze each food item**:
- **Boiled and mashed potato**: Potatoes are known to be rich in starch. When iodine is added, it will turn blue-black.
- **Boiled and charred rice**: Charred rice indicates that it has been burned, which would likely destroy any starch content. Therefore, it will not react with iodine.
- **A slice of bread**: Bread is also rich in starch. When iodine is added, it will turn blue-black.
- **Sugar solution**: Sugar does not contain starch, so it will not react with iodine and will remain unchanged.
- **Coconut oil**: Coconut oil is a fat and does not contain starch, so it will also not react with iodine.

4. **Conclusion**: The food items that will give a blue-black color when tested with iodine solution are:
- Boiled and mashed potato
- A slice of bread

### Final Answer:
The food items that will give a blue-black color when tested with iodine solution are:
1. Boiled and mashed potato
2. A slice of bread