The process of making the back ground rough, before plastering, is

Answer: Option B

Hacking: This is the process of roughening a surface before plastering. Think of it like creating a texture so the plaster has something to really grip onto. This ensures the plaster sticks well and doesn't fall off later.

Dubbing: Dubbing out refers to filling up uneven surfaces (like holes or gaps) to create a more even base before the final plaster layer.
It's more about leveling than roughening the existing surface.

Blistering: This is a *defect* in plastering, not a preparation method. It's when bubbles form under the surface.

Peeling: Similar to blistering, peeling is also a *defect* where the plaster layer starts to separate and come away from the wall.

So, to make the background rough before plastering, we use hacking to create a good bonding surface.