Which of the following is the correct sequence of ancestor of the evolution of plant forms.
a-chlorophyte, b-psilophyton, c-Rhynia type, d- Tracheophyte

Answer

To determine the correct sequence of ancestors in the evolution of plant forms, we can analyze the options given:

1. **Chlorophyte**: These are green algae that are considered the ancestors of land plants. They are the first group in the evolutionary sequence.

2. **Tracheophyte**: This group includes vascular plants that evolved from chlorophytes. They are characterized by the presence of vascular tissues (xylem and phloem) which are essential for transporting water and nutrients.

3. **Rhynia type**: This refers to a specific group of early vascular plants that lived during the early Paleozoic era. They evolved from tracheophytes and are significant in the study of plant evolution.

4. **Psilophyton**: This is a genus of primitive vascular plants that are derived from the Rhynia type. They represent an early stage in the evolution of more complex plants such as ferns, gymnosperms, and angiosperms.

Now, let's arrange these groups in the correct evolutionary sequence:

1. **Chlorophyte** (A)
2. **Tracheophyte** (D)
3. **Rhynia type** (C)
4. **Psilophyton** (B)

Thus, the correct sequence of the ancestors in the evolution of plant forms is:
**Chlorophyte → Tracheophyte → Rhynia type → Psilophyton**

### Final Answer:
The correct sequence is: **A (Chlorophyte) → D (Tracheophyte) → C (Rhynia type) → B (Psilophyton)**.