Where is the function increasing?
A1 < x < ∞1 < x < ∞
 B3 < x < ∞3 < x < ∞
 C-∞ < x < 1-∞ < x < 1
 D-∞ < x < 3-∞ < x < 3
 E-∞ < x < -1
                                             
                                          
                                          
                                       