a
\(\beta \,\, = \,\frac{{\Delta {I_C}}}{{\Delta {I_C}}}\,\,\, \Rightarrow \,\,\Delta {I_C}\,\, = \,\,\beta \Delta {I_B}\,\, = \,\,49\,\, \times \,\,5\,\mu \,A\,\, = \,\,245\,\mu A\)

\(\Delta {I_E}\,\, = \,\,\Delta {I_B}\,\, + \,\,\Delta {I_C}\,\, = \,\,5\, + \,\,245\,\, = \,\,250\,\,\mu A\)