Option 1 states that weathered rock with a change of volume is called saprolite. This statement is correct. Saprolite is a term used to describe rock that has been weathered and decomposed in place, resulting in a soft, crumbly material. The weathering process can lead to a change in the volume of the rock.

Option 2 states that the process of landscape formation by deep weathering followed by stripping of the saprolite is called etching. This statement is also correct. Etching is a geological process where deep weathering occurs, breaking down the rock into saprolite. This saprolite layer is then stripped away through erosion, revealing a distinct landscape.

Therefore, both option 1 and option 2 are correct. The weathered rock with a change of volume is called saprolite, and the process of landscape formation through deep weathering followed by stripping of the saprolite is called etching.

Overall, option 3, "Both 1 and 2", is the correct answer.