Ans = Patato


Starch (carbohydrate) is the mainly present in potato. Iodine solution is used to test the presence of starch in food materials. When iodine solution is added to a food item, it turns into blue-black colour if starch is present.  If starch is not present, then the colour will stay orange or yellow. Thus, the correct answer is option C.

Explanation:

When iodine solution is added to different foods, it reacts with starch to produce a blue-black color. Starch is a complex carbohydrate that is commonly found in plants. It serves as a storage form of glucose and is abundant in foods such as potatoes, grains, and legumes.

Reason for the answer:

The correct answer to the question is option 'c', which is potato. This is because potatoes contain a high amount of starch, and when they come into contact with iodine solution, the starch reacts with the iodine to form a blue-black color.

Explanation of other options:

- Onion: Onions do not contain a significant amount of starch, so they will not turn blue-black with iodine solution.
- Sugar: Sugar is a simple carbohydrate and does not contain starch. Therefore, it will not react with iodine solution to produce a blue-black color.
- Groundnut: Groundnuts, also known as peanuts, do not contain a high amount of starch. They mainly consist of fats and proteins, so they will not turn blue-black with iodine solution.

Conclusion:

In summary, when iodine solution is added to different foods, the one that turns blue-black is the one that contains a high amount of starch. In this case, the correct answer is potato. Onions, sugar, and groundnuts do not contain enough starch to produce a blue-black color when exposed to iodine solution.