2 . (2011•山东)优先编码器74LS147输入情况为:\( \stackrel{-}{{I}_{1}}\) \( \stackrel{-}{{I}_{3}}\) \( \stackrel{-}{{I}_{5}}\) \( \stackrel{-}{{I}_{8}}\) \( \stackrel{-}{{I}_{9}}\),为1、\( \stackrel{-}{{I}_{2}}\) \( \stackrel{-}{{I}_{4}}\) \( \stackrel{-}{{I}_{6}}\) \( \stackrel{-}{{I}_{7}}\),为0时,则编码器输出为( )
A. 0110
B. 1000 C. 0111 D. 1001