Which one of the following statements is wrong.

Options

A. Laminaria and Sargassum are used as food
B. Algae increase the level of dissovled oxygen in the immediate environment
C. Algin is obtained from red algae and carageenan from brown algae
D. Agar-agar is obtained from Gelidium and Gracilaria.

Answer

To determine which statement is wrong among the given options, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Analyze the first statement:**
- **Statement:** "Laminaria and Sargassum are used as food."
- **Analysis:** This statement is true. Both Laminaria and Sargassum are types of brown algae that are indeed used as food in various cultures.

2. **Analyze the second statement:**
- **Statement:** "Algae increases the level of dissolved oxygen in the immediate environment."
- **Analysis:** This statement is also true. Algae, particularly green algae, perform photosynthesis and release oxygen, thus increasing the level of dissolved oxygen in their surroundings.

3. **Analyze the third statement:**
- **Statement:** "Algin is obtained from red algae and carrageenan from brown algae."
- **Analysis:** This statement is incorrect. Algin is actually obtained from brown algae, while carrageenan is derived from red algae. Therefore, this statement is wrong.

4. **Analyze the fourth statement:**
- **Statement:** "Agar-agar is obtained from Gelidium and Brachylaria."
- **Analysis:** This statement is true. Agar-agar is indeed extracted from red algae, specifically from species like Gelidium and Gracilaria.

### Conclusion:
The wrong statement among the options provided is: **"Algin is obtained from red algae and carrageenan from brown algae."**