A lamppost is being raised vertically so that its height h (in meters) is increasing at 0.20 m/s. A 1.8 m tall person stands 6 m from the base of the lamppost. Let y be the distance from the lamppost to the tip of the person’s shadow measured along the ground, positive when the tip moves away from the lamppost. When the lamppost is 4 m tall, what is dtdy (in meters per second)?
a) 0.55
b) −0.45
c) 0.45
d) −0.20