A positively charged particle is released from rest in a uniform electric field. The electric potential energy of the charge.

Options

A. remains a constant because the electric field is uniform.
B. increase because the charge moves along the electric field.
C. decreases because the charge moves along the electric field.
D. decreases because the charge moves opposite to the electric field.

Explanation

To solve the problem of a positively charged particle released from rest in a uniform electric field, we can follow these steps:

### Step-by-Step Solution

1. **Understanding the Electric Field**:
- A uniform electric field is defined as a region where the electric force is constant in magnitude and direction. For a positively charged particle, the force acting on it will be in the direction of the electric field.

2. **Initial Conditions**:
- The positively charged particle is released from rest, meaning its initial velocity is zero. At this point, it has a certain electric potential energy due to its position in the electric field.

3. **Movement of the Charged Particle**:
- Once released, the positively charged particle will experience a force due to the electric field, causing it to accelerate in the direction of the field. This means that the particle will move from a region of higher electric potential to a region of lower electric potential.

4. **Change in Electric Potential Energy**:
- As the particle moves in the direction of the electric field, its electric potential energy decreases. This is because electric potential energy (U) is given by the equation:
\[ U = qV \]
where \( q \) is the charge of the particle and \( V \) is the electric potential. As the particle moves to a lower potential (V decreases), the electric potential energy (U) also decreases.

5. **Conclusion**:
- Therefore, we conclude that the electric potential energy of the positively charged particle decreases as it moves in the direction of the electric field.

### Summary of Key Points:
- The positively charged particle moves in the direction of the electric field.
- As it moves, it transitions from a higher potential to a lower potential.
- Consequently, its electric potential energy decreases.