The correct combination of characters regarding slime molds is

Options

A. parasitic, plasmodium with true walls, spores dispersed by air currents
B. parasitic, plasmodium without walls, spores dispersed by water
C. saprophytic, plasmodium without walls, spores dispersed by water
D. saprophytic, plasmodium without walls, spores dispersed by air currents.

Answer

To determine the correct combination of characters regarding slime molds, we need to analyze the provided options based on the characteristics of slime molds.

### Step-by-Step Solution:

1. **Understanding Slime Molds**:
- Slime molds are a group of eukaryotic organisms that are neither fungi nor plants. They can exist in two main forms: as a single-celled organism or as a multicellular structure called plasmodium.

2. **Analyzing the Options**:
- **Option 1**: "A parasitic plasmodium with two walls, spores dispersed by air currents."
- **Analysis**: This option is incorrect because slime molds are saprophytic (they feed on dead organic matter) and do not have two walls. They do not form a parasitic plasmodium.

- **Option 2**: "Parasitic plasmodium without walls, spores dispersed by water."
- **Analysis**: This option is also incorrect. While slime molds do not have walls, they are not parasitic, and their spores are dispersed by air currents, not water.

- **Option 3**: "Saprophytic plasmodium without walls, spores dispersed by water currents."
- **Analysis**: This option is incorrect as well. Although it correctly identifies slime molds as saprophytic and without walls, it incorrectly states that spores are dispersed by water currents.

- **Option 4**: "Saprophytic plasmodium without walls, spores dispersed by air currents."
- **Analysis**: This option is correct. Slime molds are indeed saprophytic, their plasmodium does not have walls, and their spores are dispersed by air currents.

3. **Conclusion**:
- The correct combination of characters regarding slime molds is found in **Option 4**: "Saprophytic plasmodium without walls, spores dispersed by air currents."

### Final Answer:
**Option 4**: Saprophytic plasmodium without walls, spores dispersed by air currents.

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