For the differential equation dxdy=y with initial condition y(0)=1, a student follows the slope field by drawing successive tangent segments of length 0.2 in the x-direction. Starting at (0,1) and continuing in the positive x-direction, which value is the most reasonable estimate of y when x=0.4?
a) 1.64
b) 1.44
c) 1.49
d) 1.40