In a Portal system (Man) `:-`

Options

A. a vein starts from an organ and ends up in the heart
B. an artery breaks up in an organ and restarts by union of capillary
C. a vein enters into an organ other than the heart and breaks up into capillaries
D. the blood from gut is brought into kidneys before it is poured into posterior vena cava

Answer

### Step-by-Step Solution:

1. **Understanding the Portal System**:
- A portal system is a type of circulatory system where blood flows from one organ to another through a set of capillaries before returning to the heart. This is different from the typical circulation where blood goes directly from the heart to an organ.

2. **Identifying the Components**:
- In a portal system, there is a specific vein known as the portal vein that carries blood from one organ (like the intestines) to another organ (like the liver) through capillaries.

3. **Analyzing the Given Statements**:
- The question provides several statements about veins and arteries in the context of a portal system. We need to evaluate each statement to find the correct one.

4. **Evaluating Each Option**:
- **Option 1**: "A vein starts from an organ and ends up in the heart."
- This is incorrect because a portal vein does not end in the heart.
- **Option 2**: "An artery breaks up in an organ and restarts by the union of capillaries."
- This describes a typical arterial system, not a portal system.
- **Option 3**: "A vein enters into an organ other than the heart and breaks up into capillaries."
- This is the correct description of how a portal vein functions.
- **Option 4**: "The blood from the gut is brought into the kidneys before it pours into the posterior vena cava."
- This is incorrect; blood from the gut goes to the liver, not the kidneys.

5. **Conclusion**:
- The correct answer is **Option 3**: "A vein enters into an organ other than the heart and breaks up into capillaries."