help please!

Determine a value of the constant a for which lim g(x) exists and state the value of the limit, if possible. X- - 1 x2 - 4x ifxs- 1 g(x) = ax" - 8 ifx> - 1 Select the correct choice below and, if necessary, fill in the answer boxes to complete your choice. O A. The limit exists for a = With that value for a, lim g(x) = X - - 1 O B. There is no value of a for which lim g(x) exists. X- - 1