答案：D
$\begin{array}{rcl}
x^2-6x & = & 2-k \\
x^2-6x +(k-2) & = & 0
\end{array}$
$\begin{array}{rcl}
x^2-6x & = & 2-k \\
x^2-6x +(k-2) & = & 0
\end{array}$
該二次方程沒有實根，因此 $\Delta <0$。由此，可得
$\begin{array}{rcl}
(-6)^2 – 4(1)(k-2) & < & 0 \\
36 -4k+8 & < & 0 \\
4k & > & 44 \\
k & > & 11
\end{array}$
