A student is running a 3-kilometer race. He runs 1 kilometer every 2 minutes. Select the function that describes his distance from the finish line after x minutes. (1 point)
f(x) = − 1/3 x + 2
f(x) = − 1/2 x + 3
f(x) = 1/2 x + 3
f(x) = 1/3 x + 2