Physics · JEE | Electrostatic Potential and Capacitance

A test charge \( q \) is moved slowly from point \( \text{R} \) to point \( \text{P} \) against a repulsive electrostatic force due to a source charge \( Q > 0 \) placed at the origin. If the work done by the external force is \( W_{RP} \), the potential energy difference \( \Delta U = U_P - U_R \) is given by:

1. A
   \( -W_{RP} \)
2. B
   \( \frac{1}{2} W_{RP} \)
3. C
   \( W_{RP} \)
4. D
   \( 2W_{RP} \)