Which of the followings are required for blood clotting

Options

A. `K^(+)`, Thromboplastin
B. `Ca^(++)` thromboplastin
C. `Na^(+), Ca^(++)`
D. `K^(+)`, prothrombin

Explanation

To answer the question "Which of the followings are required for blood clotting," we can follow these steps:

### Step-by-Step Solution:

1. **Identify Key Components of Blood Clotting**: Blood clotting, also known as coagulation, involves several components that work together to form a clot. The primary components include platelets, clotting factors, and certain ions.

2. **List the Required Substances**: From the video transcript, the substances mentioned that are required for blood clotting include:
- Calcium
- Thromboplastin
- Thrombin

3. **Understand the Role of Each Component**:
- **Calcium**: This ion is essential for various steps in the coagulation cascade. It helps in the activation of several clotting factors.
- **Thromboplastin**: This is a tissue factor that initiates the clotting process by activating the clotting cascade.
- **Thrombin**: This enzyme converts fibrinogen into fibrin, which is crucial for the formation of a stable blood clot.

4. **Eliminate Incorrect Options**: The question may provide multiple options. Based on the information from the transcript, sodium and iron are not directly mentioned as necessary for blood clotting in this context.

5. **Conclude with the Correct Answer**: Based on the analysis, the substances required for blood clotting are Calcium and Thromboplastin.

### Final Answer:
The components required for blood clotting are Calcium and Thromboplastin.

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