What is the range of f(x)=4−exf(x) = 4 - e^xf(x)=4−ex?
(4,∞)(4, \infty)(4,∞)
(−∞,4)(-\infty, 4)(−∞,4)
(0,4)(0, 4)(0,4)
(−∞,4](-\infty, 4](−∞,4]