Multinucleate muscle cells are
(a) Cardiac muscles
(b) Smooth muscles
(c) Skeletal muscles
(d) Both a and c

Options

A. Cardiac muscles
B. Smooth muscles
C. Skeletal muscles
D. Both a and c

Answer

To solve the question regarding which muscle cells are multinucleate, we can analyze each of the provided options step by step.

### Step-by-Step Solution:

1. **Understanding Skeletal Muscles**:
- Skeletal muscles are a type of striated muscle.
- They are characterized by having multiple nuclei within a single muscle fiber, making them multinucleate.
- Skeletal muscles are also voluntary, meaning they can be consciously controlled.

2. **Understanding Cardiac Muscles**:
- Cardiac muscles are found in the heart and are responsible for pumping blood.
- They are also striated but are involuntary, meaning they function without conscious control.
- Cardiac muscle cells can be multinucleate, although they are typically described as having one or two nuclei.

3. **Understanding Smooth Muscles**:
- Smooth muscles are found in the walls of internal organs and blood vessels.
- They are not striated and are involuntary.
- Smooth muscle cells are typically uninucleate, meaning they contain a single nucleus.

4. **Analyzing the Options**:
- Option (a) Cardiac muscles: Multinucleate.
- Option (b) Smooth muscles: Uninucleate.
- Option (c) Skeletal muscles: Multinucleate.
- Option (d) Both a and c: This option suggests that both cardiac and skeletal muscles are multinucleate.

5. **Conclusion**:
- Since both cardiac muscles (option a) and skeletal muscles (option c) are multinucleate, the correct answer is option (d) Both a and c.

### Final Answer:
**(d) Both a and c**