Muscles develop from

Options

A. Ectoderm
B. Mesoderm
C. Endoderm
D. All the above .

Answer

### Step-by-Step Solution:

1. **Understanding Germ Layers**: In embryonic development, there are three primary germ layers: ectoderm, mesoderm, and endoderm. Each of these layers gives rise to different tissues and organs in the body.

2. **Identifying the Role of Each Layer**:
- **Ectoderm**: This layer primarily develops into the skin and nervous system.
- **Endoderm**: This layer forms the lining of the gastrointestinal tract and associated organs.
- **Mesoderm**: This layer is responsible for developing into muscles, connective tissues, bones, and the circulatory system.

3. **Focusing on Muscle Development**: Muscles are specifically derived from the mesoderm. This includes all three types of muscles:
- **Cardiac Muscle**: Found in the heart.
- **Smooth Muscle**: Located in the walls of hollow organs (like the intestines and blood vessels).
- **Skeletal Muscle**: Attached to bones and responsible for voluntary movements.

4. **Conclusion**: Since muscles develop from the mesoderm, the correct answer to the question "Muscles develop from" is the mesoderm.

### Final Answer:
Muscles develop from the **mesoderm**.

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