The main differentiating factor between non-vascular and vascular plants is -

Options

A. Lack of gametophyte
B. Spore production
C. The presence of tracheids
D. All

Answer

To answer the question about the main differentiating factor between non-vascular and vascular plants, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Definitions**:
- **Non-Vascular Plants**: These are plants that do not have specialized tissues for the transport of water and nutrients. Examples include mosses and liverworts.
- **Vascular Plants**: These plants have specialized tissues (xylem and phloem) that transport water, nutrients, and food throughout the plant. Examples include ferns, conifers, and flowering plants.

2. **Identify Key Features**:
- Non-vascular plants rely on diffusion and osmosis for the movement of water and nutrients.
- Vascular plants possess xylem (for water and mineral transport) and phloem (for food transport).

3. **Analyze the Options**:
- Option 1 mentions "lack of gametophytes" which is not a main differentiating factor.
- Option 2 refers to "spore formation" which is common in both types of plants.
- Option 3 states "the presence of tracheids" which are indeed part of the xylem in vascular plants.
- Option 4 suggests "all" which is incorrect since not all options are differentiating factors.

4. **Conclusion**:
- The main differentiating factor between non-vascular and vascular plants is the presence of xylem and phloem. Therefore, the correct answer is **Option 3**.

### Final Answer:
The main differentiating factor between non-vascular and vascular plants is the presence of xylem and phloem.

---