The electric dipole moment of a short electric dipole is $p$. The electric potential at a point at a distance $r$ from its center and making an angle $\theta$ with the axis of the dipole is .......

• A
  $\frac{kp \sin \theta}{r^2}$
• B
  $\frac{kp \cos \theta}{r^2}$
• C
  $\frac{kp}{r^3} \sqrt{1 + 3 \cos^2 \theta}$
• D
  $\frac{kp}{r^3} \sqrt{1 + 3 \sin^2 \theta}$