Question

Jack is working with layer masks on an image, but he is worried that he may damage the image. Which of these would be an accurate fact about layer masks? The layer mask permanently changes all parts of an image.
The layer mask changes some parts of a layer and affects some parts of an image. The layer mask permanently changes parts of a layer and affects all parts of an image.
The layer mask hides parts of a layer without damaging any part of an image.

Answer 1

Masking layers is a much-appreciated compositing technique for combining photos into a single image or for removing objects from a photo.
So, an accurate fact about layer masks is that the layer mask permanently changes parts of a layer and affects all parts of an image. 

Answer: The layer mask hides parts of a layer without damaging any part of an image.