Which of the following is true regarding the source and nature of the enamel?

Options

A. Odontoblast, mesodermal
B. Odontoblast, ectodermal
C. Ameloblast, mesodermal
D. Ameloblast, ectodermal

Answer

### Step-by-Step Solution:

1. **Understanding Enamel**: Enamel is the outermost layer of human teeth. It is the hardest substance in the human body and serves to protect the underlying structures of the teeth.

2. **Origin of Enamel**: The nature of enamel is ectodermal in origin. This means that it develops from the ectoderm layer of the embryo during the process of tooth development.

3. **Cells Involved in Enamel Formation**: Enamel is secreted by specialized cells known as ameloblasts. These cells are responsible for the production of enamel during tooth development.

4. **Comparison with Dentine**: It is important to note that beneath the enamel is dentine, which is a different structure. Dentine is mesodermal in origin and is secreted by odontoblast cells. This distinction helps to clarify the source of both enamel and dentine.

5. **Conclusion**: Based on the information, the correct statement regarding the source and nature of enamel is that it is derived from ameloblast cells and is ectodermal in origin.

### Final Answer:
The enamel is secreted by ameloblast cells and is ectodermal in origin.

---