If f(x)=x2+4x+4=(x+2)2f(x) = x^2 + 4x + 4 = (x+2)^2f(x)=x2+4x+4=(x+2)2, what is the range of fff on its domain?
[0,∞)[0, \infty)[0,∞)
[4,∞)[4, \infty)[4,∞)
(0,∞)(0, \infty)(0,∞)
R\mathbb{R}R