An oil well off the Gulf Coast is leaking, with the leak spreading oil over the water’s surface as a circle. At any time t, in minutes, after the beginning of the leak, the radius of the circular oil slick on the surface is r(t) = 4t feet. Let A(r) = πr² represent the area of a circle of radius r.

(a) Find (A ° r)(t).

(b) Interpret (A ° r)(t).

(c) What is the area of the oil slick after 3 min?