Assertion: The middle piece is called as power house of the sperm.
Reason: The numerous mitochondria coiling around axial filament produce energy for the movement of the tail.

Explanation

To solve the assertion and reason question, we will break it down step by step:

### Step 1: Understand the Assertion
The assertion states that "The middle piece is called the powerhouse of the sperm."
- The middle piece of the sperm is indeed often referred to as the powerhouse because it contains a high concentration of mitochondria.

**Hint:** Think about the role of mitochondria in cells and why they are termed "powerhouses."

### Step 2: Understand the Reason
The reason states that "The numerous mitochondria coiling around the axial filament produce energy for the movement of the tail."
- Mitochondria are organelles responsible for producing ATP (adenosine triphosphate), which is the energy currency of the cell. In sperm, the energy produced by mitochondria is crucial for the motility of the tail, enabling the sperm to swim towards the ovum.

**Hint:** Consider how energy production is linked to movement in cells, especially in the context of sperm motility.

### Step 3: Analyze the Relationship Between Assertion and Reason
Now, we need to determine if both the assertion and the reason are true and if the reason correctly explains the assertion.
- Since the middle piece does contain mitochondria that provide energy for the sperm's movement, both the assertion and the reason are true. The reason accurately explains why the middle piece is referred to as the powerhouse.

**Hint:** Reflect on how the structure and function of a cell part can explain its nickname or role.

### Step 4: Conclusion
Based on the analysis, we can conclude that both statements are correct, and the reason correctly explains the assertion.

**Final Answer:** The correct option is A: Both statements are correct, and the reason is correctly explaining the assertion.