Correct statement of the following with regard to active transport is

Options

A. Takes place against the concentration gradient
B. Carrier proteins involved in active transport are called ‘pumps’
C. It is an uphill transport
D. all the above

Answer

### Step-by-Step Solution:

1. **Understanding Active Transport**:
- Active transport is a process that moves substances across a cell membrane from an area of lower concentration to an area of higher concentration. This process is essential for maintaining cellular functions and requires energy.

2. **Analyzing the Statements**:
- **Statement 1**: "Takes place against the concentration gradient."
- This statement is true because active transport moves substances from low concentration to high concentration, which is against the concentration gradient.

- **Statement 2**: "Carrier proteins involved in active transport are called pumps."
- This statement is also true. The proteins that facilitate active transport are indeed referred to as pumps.

- **Statement 3**: "It is an uphill transport."
- This statement is true as well. Since active transport moves substances from a lower concentration to a higher concentration, it is considered uphill transport.

3. **Conclusion**:
- Since all three statements (1, 2, and 3) are correct, the correct answer is **"All of the above."**

### Final Answer:
The correct statement with regard to active transport is **"All of the above."**

---