Final answer:
The graph is positive on (-6, -2).
Step-by-step explanation:
The polynomial function with the given roots is expressed as:
f(x) = a(x + 6)(x + 2)^3(x)(x - 4)^3
Since the function has a positive leading coefficient and is of odd degree, the graph will start in the third quadrant and end in the first quadrant. Therefore, the graph is positive on the intervals (-6, -2) and (0, 4).
So, the correct statement is: a. The graph is positive on (-6, -2).