Find the range of f(x)=1x2+4x+5f(x) = \frac{1}{x^2 + 4x + 5}f(x)=x2+4x+51.
(0,1](0, 1](0,1]
[0,1][0, 1][0,1]
(0,∞)(0, \infty)(0,∞)
[1,∞)[1, \infty)[1,∞)