All fungi are :

Options

A. symbionts
B. heterotrophs
C. saprophytes
D. parasites

Explanation

To solve the question "All fungi are:", we will analyze each option provided and determine the correct classification of fungi based on their characteristics.

### Step-by-Step Solution:

1. **Understanding Fungi**:
- Fungi belong to the kingdom Fungi, which is a separate kingdom in biological classification. They are primarily eukaryotic organisms, meaning their cells have a nucleus.

**Hint**: Remember that fungi are classified in their own kingdom due to their unique characteristics.

2. **Cell Structure**:
- Most fungi are multicellular, with the exception of yeast, which is unicellular. The cell walls of fungi are made of chitin, which is a distinguishing feature.

**Hint**: Identify the structural components of fungi, such as their cell wall composition.

3. **Mode of Nutrition**:
- Fungi are heterotrophs, meaning they cannot produce their own food and must obtain it from other sources. They primarily follow a saprotrophic mode of nutrition, where they decompose dead organic matter.

**Hint**: Focus on the nutritional habits of fungi to understand their classification.

4. **Analyzing the Options**:
- **Option A: Symbionts** - Symbionts engage in mutual relationships with other organisms. While some fungi can form symbiotic relationships (like mycorrhizae), this is not true for all fungi.
- **Option B: Heterotrophs** - This is accurate because fungi do depend on other organisms for food. However, this option is too broad.
- **Option C: Cephalophytes** - This term does not apply to fungi and is incorrect.
- **Option D: Parasites** - While some fungi can be parasitic, not all fungi are parasites.

**Hint**: Evaluate each option carefully based on the characteristics of fungi.

5. **Conclusion**:
- The most accurate option that describes all fungi is **Option B: Heterotrophs**. This is because all fungi obtain their nutrients from other sources, primarily through decomposing organic matter.

**Hint**: The key characteristic that applies to all fungi is their heterotrophic nature.

### Final Answer:
All fungi are **heterotrophs**.