The interaction energy of London force is inversely proportional to sixth power of the distance between two interacting particles. Their magnitude depends upon-

1. Charge of interacting particles.

2. Mass of interacting particles.

3. Polarizability of interacting particles.

4. Strength of permanent dipoles in the particles.

Hint: London dispersion forces operate only over very short distances.

Explanation:
The energy of interaction varies as 1(distance between two interacting particles)6
Large or more complex are the molecules, greater is the magnitude of London forces. This is obviously due to the fact that the large electron clouds are easily distorted or polarised.
Hence, the greater the polarizability of the interacting particles, the greater is the magnitude of the interaction energy.