66 The function $f(x)$ is defined on all real numbers and is an even function. Its graph is symmetric about the line $x=2$. It is known that when $x \in[-2,2]$, the expression for $f(x)$ is $-x^{2}+1$. Then, when $x \in[6,10]$, the expression for $f(x)$ is
A. $-(x-8)^{2}+1$
B. $-(x-2)^{2}+1$
C. $-(x-4)^{2}+1$
D. $-x^{2}+1$
66 A. According to the problem, $f(x)$ is a periodic function with a period of 4, so when $x \in [6,10]$, $f(x) = -(x-8)^2 + 1$.