Need urgently : (

the graph of the derivative, f '(x) is shown below. on what interval is the graph of f (x) concave up?

graph is a parabola with x intercepts at x equals negative 4 and 2 and y intercept at y equals negative 2

concave up on (−∞, −1)
concave up on (−∞, −∞)
concave up on (−1, ∞)
concave up on (−6, −2)