The given equation of the line is \( y = -x + 6 \).
In the slope-intercept form of a line, \( y = mx + b \), \( m \) represents the slope, and \( b \) represents the y-intercept.
From the equation \( y = -x + 6 \):
- The slope \( m \) is \(-1\).
- The y-intercept \( b \) is \(6\).
Therefore, the correct answer is:
C. The slope is -1, and the y-intercept is 6.