10. An electric dipole with a dipole moment magnitude of p = 5.0 × 10⁻⁶ C·m is placed in a uniform electric field of magnitude E = 2.0 × 10⁵ N/C. The initial angle between the dipole moment and the electric fieldis 60°. How much work must an external agent do to turn the dipole 180° from its initial position? (A) 0.5 J (B) 1.0 J (C) 1.5 J (D) 2.0 J (E) 0 J