What is a key non-destructive advantage of using layer masks?

• A. They permanently erase portions of a layer.
• B. They non-destructively hide or reveal parts of a layer, without deleting pixels.
• C. They apply color adjustments globally.
• D. They convert the image to grayscale.

Answer: (B)

Layer masks give you a non-destructive way to control which parts of a layer are visible. Instead of erasing pixels, you paint on the mask to hide or reveal areas. Painting with black hides, white reveals, and shades of gray create partial transparency, so you can blend and adjust without permanently changing the image data. The pixels on the layer stay intact, making edits reversible—toggle the mask on or off, or repaint to restore areas. This makes masking ideal for compositing, retouching, and applying adjustments selectively, because you can refine your edges, blend softly with gradients, or rework a section at any time without destroying the original pixels. In short, the key non-destructive advantage is that layer masks control visibility without deleting or altering the underlying image.