4. The even function $f(x)$ defined on $\mathbf{R}$ satisfies $f(x+1)=-f(x)$,
and is increasing in the interval $[-1,0]$, then ().
(A) $f(3)<f(\sqrt{3})<f(2)$
(B) $f(2)<f(3)<f(\sqrt{3})$
(C) $f(3)<f(2)<f(\sqrt{3})$
(D) $f(2)<f(\sqrt{3})<f(3)$