$\begin{array}{1 1}(A)\;C=\{-2,-1,0,1,2,3,4,5,6\}\\(B)\;C=\{0,1,2,3,4,5,6\}\\(C)\;C=\{-2,-1,0,1,2\}\\(D)\;C=\{5,6\}\end{array} $