3. Let $a>1$, then for any $x \in(1, a)$ we have
A. $\log _{a}\left(\log _{0} x\right)<\log _{a} x^{2}<\left(\log _{a} x\right)^{2}$
B. $\log _{a}\left(\log _{a} x\right)<\left(\log _{a} x\right)^{2}<\log _{a} x^{2}$
C. $\log _{a} x^{2}<\log _{a}\left(\log _{a} x\right)<\left(\log _{a} x\right)^{2}$
D. $\left(\log _{a} x\right)^{2}<\log _{a} x^{2}<\log _{a}\left(\log _{a} x\right)$
3. B $0<\log _{a} x<\log _{a} a=1$, so $\log _{a}\left(\log _{a} x\right)<0, \log _{a} x^{2}=2 \log _{a} x$ obviously $\log _{a} x<2$, thus $\left(\log _{a} x\right)^{2}<$ $2 \log _{a} x=\log _{a} x^{2}$