Which statement correctly describes the monotonic behaviour of the two curves y=4x and y=(41)x?
a) y=4x is increasing for x>0 and decreasing for x<0, whereas y=(41)x is decreasing for x>0 and increasing for x<0
b) Both curves are decreasing for all real x.
c) y=4x is increasing, whereas y=(41)x is decreasing.
d) Both curves are increasing for all real x.