It is observed that the mean line of the data should pass through the points (3,3), (2,4), (1,5), (0,6), (-1,7).
Consider that the equation of a line passing through two given points is given by,
![y-y_1=(y_2-y_1)/(x_2-x_1)(x-x_1)](https://img.qammunity.org/2023/formulas/mathematics/college/hkbzvop4iz62zgm93u190774353c4ig6id.png)
So the equation of the best fit line passing through (3,3) and (0,6) will be,
![\begin{gathered} y-3=(6-3)/(0-3)(x-3) \\ y-3=(3)/(-3)(x-3) \\ y-3=-(x-3) \\ y-3=-x+3 \\ y=-x+6 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/3ukkt539j7gc4ngq0ee55f62vkj5b7ipa5.png)
Thus, option C is the correct choice.