Among rust, smut and mushroom, all the three

Options

A. are pathogens
B. are saprobes
C. bear ascocarps
D. bear basidiocarps

Explanation

To solve the question regarding rust, smut, and mushrooms, we need to analyze each option provided and determine which one correctly describes the relationship among these three types of fungi.

### Step-by-Step Solution:

1. **Identify the Types of Fungi**:
- Rust and smut are both types of fungi that belong to the group known as Basidiomycetes. Rust fungi belong to the order Uredinales, while smut fungi belong to the order Ustilaginales.
- Mushrooms are also part of the Basidiomycetes group.

2. **Examine the Options**:
- **Option A: Pathogens**: While rust and smut are pathogens (disease-causing organisms), many mushrooms are not pathogens; they can be edible or poisonous. Therefore, this option is incorrect.
- **Option B: Saprotrophs**: Saprotrophs are organisms that feed on decaying organic matter. While some mushrooms can be saprotrophic, rust and smut are not. Thus, this option is also incorrect.
- **Option C: Ascocarps**: Ascocarps are the fruiting bodies of Ascomycetes, a different group of fungi. Since rust, smut, and mushrooms belong to Basidiomycetes, this option is incorrect.
- **Option D: Basidiocarps**: Basidiocarps are the fruiting bodies of Basidiomycetes fungi, which include rust, smut, and mushrooms. This option is correct.

3. **Conclusion**: The correct answer is that rust, smut, and mushrooms bear Basidiocarps.

### Final Answer:
The correct option is **D: They bear Basidiocarps**.