If dy/dx=1/x, then the average rate of change of y with respect to x on the closed interval [1, 4] is
A-1/4
B(1/2)ln(2)
C(2/3)ln(2)
D2/5
E2
A-1/4
B(1/2)ln(2)
C(2/3)ln(2)
D2/5
E2