Question

Which condition causes rocks to exhibit ductile deformation?

Answer 1

The answer is - Unlithified or poorly lithified sediments.

Rocks can exhibit ductility only if there's ulithified or poorly lithified sediments. With other words, this process can occur only if the rocks that are bending over under the pressure if there's soft layer/layers that will allow this to happen without causing big opposing pressure and make the rocks break.