On a slope field printed so that one horizontal grid square represents Δx=0.2 and one vertical grid square represents Δy=1, a curve satisfying dxdy=x−y passes through (0,2). A student constructs an Euler polygonal path by moving three grid squares to the right, using the slope at each new point to determine the next segment. Which value is the best estimate of y after the third step?
a) 1.14
b) 0.92
c) 1.60
d) 1.20