Find the sum of the roots of the quadratic equation 6 − x − x2 = 0.

The given equation is $6 - x - x^2 = 0$.
Rearranging the terms to match $ax^2 + bx + c = 0$:
$-x^2 - x + 6 = 0$
To make the leading coefficient positive, we can multiply the entire equation by -1:
$x^2 + x - 6 = 0$

From the equation $x^2 + x - 6 = 0$, we have:
$a = 1$
$b = 1$
$c = -6$

The roots are $c$ and $k$, so their sum is $c+k$.
Using the formula for the sum of the roots:

Substitute the values of $a$ and $b$:

The sum of the roots is -1.

Comparing this with the given options:
A. 2
B. 1
C. -1
D. -3

The correct option is C.

The final answer is $\boxed{\text{C. -1}}$.