In slime moulds :-
(a) The main body is wall less
(b) True wall is found around spores
(c) Spores are dispersed by water
(d) Saprophytes are not common

Options

A. a, b are correct
B. a, c are correct
C. b, d are correct
D. a, d correct

Answer

To solve the question regarding slime moulds, we need to evaluate each statement provided:

1. **Statement (a): The main body is wall-less.**
- Slime moulds are known for their unique structure. They exist in a plasmodial form, which is a mass of protoplasm that is not divided into cells and does not have cell walls. Therefore, this statement is **true**.

2. **Statement (b): True wall is found around spores.**
- In slime moulds, when they reproduce, they form spores that are indeed surrounded by a wall. This wall is a protective structure that helps in the survival of the spores. Hence, this statement is also **true**.

3. **Statement (c): Spores are dispersed by water.**
- Spores of slime moulds are primarily dispersed by wind, not water. This means that this statement is **false**.

4. **Statement (d): Saprophytes are not common.**
- Slime moulds are typically saprophytic, meaning they feed on decaying organic matter. They are quite common in nature as decomposers. Therefore, this statement is also **false**.

Now, summarizing the evaluations:
- Statements (a) and (b) are correct.
- Statements (c) and (d) are incorrect.

Thus, the correct answer is **option (a)**: that is, statements (a) and (b) are correct.

### Step-by-Step Solution:
1. **Evaluate Statement (a)**: Confirm that slime moulds have a wall-less main body. (True)
2. **Evaluate Statement (b)**: Check if true walls are found around spores. (True)
3. **Evaluate Statement (c)**: Determine the method of spore dispersion. (False - they are dispersed by wind)
4. **Evaluate Statement (d)**: Assess the commonality of saprophytes. (False - they are common)
5. **Conclusion**: Identify the correct option based on the evaluations. (Option a is correct)