Which of the following is correct

Options

A. Mesoderm produces brain
B. Ectoderm produces liver
C. Mesoderm produces skeleton
D. Endoderm produces heart

Explanation

### Step-by-Step Solution:

1. **Understanding Germ Layers**: In embryonic development, there are three primary germ layers: ectoderm, mesoderm, and endoderm. Each layer differentiates into specific tissues and organs.

2. **Identifying the Functions of Each Germ Layer**:
- **Ectoderm**: This layer primarily develops into the nervous system and skin. It is responsible for producing the brain and spinal cord.
- **Mesoderm**: This layer is responsible for forming structures such as muscles, bones (skeleton), and the circulatory system. It plays a crucial role in developing the skeleton.
- **Endoderm**: This layer forms the internal organs, including the liver and digestive tract. It does not produce the heart; rather, the heart is derived from mesoderm.

3. **Evaluating the Given Options**:
- The statement "mesoderm produces brain" is incorrect; the brain is produced by the ectoderm.
- The statement "ectoderm produces liver" is incorrect; the liver is produced by the endoderm.
- The statement "mesoderm produces skeleton" is correct.
- The statement "endoderm produces heart" is incorrect; the heart is produced by mesoderm.

4. **Conclusion**: Based on the analysis, the only correct statement is that the mesoderm produces the skeleton. Therefore, the correct answer is option C.