How do you apply a mask to fade a subject into the background using gradient masking?

How do you apply a mask to fade a subject into the background using gradient masking?

• A. Add a layer mask to the background; use Gradient Tool on the mask from white to black to fade
• B. Add a layer mask to the subject; use Brush Tool with white color to fade
• C. Add a layer mask to the subject; select Gradient Tool and drag on the mask from opaque to transparent to fade the subject into background; white reveals, black hides
• D. Add a gradient fill layer above the subject

Answer: (C)