Answer: C.châtains
Step-by-step explanation: This is because "châtains" refers to a shade of brown, which can be used to describe hair color, but not eye color.
Let's look at the other options:
- "Bleus" (Option A) can be used to describe blue eyes.
- "Verts" (Option B) can be used to describe green eyes.
- "Marrons" (Option D) can be used to describe brown eyes.