Food reserve in Rhodophyta is :-

Options

A. Floridean starch
B. Mannitol
C. Leucosin
D. All of the above

Answer

To determine the food reserve in Rhodophyta (red algae), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Group**: Recognize that Rhodophyta refers to red algae, which are a distinct group of algae characterized by their red pigmentation due to phycoerythrin.

2. **Understand Food Reserves in Algae**: Different groups of algae have different types of food reserves. It's essential to know what these reserves are for each group.

3. **Analyze the Options**:
- **Floridian Starch**: This is a type of starch that is specifically known to be the food reserve in Rhodophyta.
- **Mannitol**: This is primarily the food reserve for brown algae (Phaeophyta).
- **Leucosin**: This carbohydrate is typically the reserve food material for yellowish-green algae (Chrysophyta).
- **All of the Above**: This option suggests that all the mentioned substances are food reserves for Rhodophyta, which is incorrect.

4. **Select the Correct Answer**: Based on the information, the food reserve specific to Rhodophyta is Floridian starch.

5. **Conclusion**: Therefore, the correct answer to the question "Food reserve in Rhodophyta is:" is **Floridian starch**.

### Final Answer:
The food reserve in Rhodophyta is **Floridian starch**.