Deflation is the movement of dust, sand, and rock caused by

Out of the following given choices;

The answer is; wind.

This mostly occurs in regions where there are loose sediments such as in deserts. The particles are able to be carried by the wind and deposited elsewhere to form a loess deposit. This deflation mya dee deep furrows and hollows or blowouts that can be even deep enough to reach the water table in the eroded environment. An example of a geographical feature caused by deflation is The Big Hollow in Wyoming which is 14.5 km (9 miles) in length and 50 m (165 feet) depth.

force required to detach it is given by

charges are taken to be fundamental charge

now we have

so above is the minimum distance at which it will detach