Answer: Option C
$$\eqalign{
& \,\,\,\,\,\,1|\overline 1 \,\,\overline {58} \,\,\overline {76} \,(126 \cr
& \,\,\,\,\,\,\,\,\,|1 \cr
& \,\,\,\,\,\,\,\,\,| - - - - - - - - \cr
& \,\,22|\,\,\,\,\,\,58 \cr
& \,\,\,\,\,\,\,\,\,|\,\,\,\,\,\,44 \cr
& \,\,\,\,\,\,\,\,\,| - - - - - - - - \cr
& 246\,|\,\,\,\,\,\,\,14\,76 \cr
& \,\,\,\,\,\,\,\,\,|\,\,\,\,\,\,\,\,14\,76 \cr
& \,\,\,\,\,\,\,\,\,| - - - - - - - \cr
& \,\,\,\,\,\,\,\,\,|\,\,\,\,\,\,\,\,\,\,\,\,\,x \cr
& \,\,\,\,\,\,\,\,\,| - - - - - - - \cr
& \therefore \sqrt {15876} = 126 \cr} $$