Spongy or cancellous bones are:
(1) Skull bones (2) Vertebrae (3) Femur (4) Ribs

Options

A. 1,2 and 3 are correct
B. 1 and 2 are correct
C. 2 and 4 are correct
D. 1 and 3 are correct

Answer

To determine which of the given options are spongy or cancellous bones, we need to analyze each option based on the characteristics of spongy bones.

### Step-by-Step Solution:

1. **Understanding Spongy Bones**:
- Spongy bones, also known as cancellous bones, are characterized by their porous structure. They are typically found at the ends of long bones and are rich in blood supply.

2. **Analyzing Option 1: Skull Bones**:
- Skull bones are primarily made of compact bone and do not exhibit the characteristics of spongy bone. Therefore, this option is incorrect.

3. **Analyzing Option 2: Vertebrae**:
- The vertebrae are indeed made up of spongy bone. They have a central cavity filled with bone marrow and are designed to support weight and provide flexibility to the spine. This option is correct.

4. **Analyzing Option 3: Femur**:
- The femur is a long bone, and while it does have spongy bone at its ends (the epiphyses), the entire femur is not classified as spongy bone. Thus, this option is incorrect.

5. **Analyzing Option 4: Ribs**:
- Ribs are primarily made of flat bones and do not consist of spongy bone throughout. They have some spongy bone at the ends, but they are not classified as spongy bones overall. Therefore, this option is also incorrect.

6. **Conclusion**:
- The only option that correctly identifies spongy or cancellous bones is Option 2: Vertebrae.

### Final Answer:
The correct answer is **(2) Vertebrae**.