What are the features of the quadratic function ƒ(x) = x2 + 10x + 21? A) Vertex = (–4,–5), y-intercept = (0,21), x-intercepts = (–7,0) and (–3,0), axis of symmetry is x = –4

B) Vertex = (5,4), y-intercept = (0,–21), x-intercepts = (–7,0) and (–3,0), axis of symmetry is x = 5

C) Vertex = (–5,–4), y-intercept = (21,0), x-intercepts = (3,0) and (7,0), axis of symmetry is x = –5

D) Vertex = (–5,–4), y-intercept = (0,21), x-intercepts = (–7,0) and (–3,0), axis of symmetry is x = –5