Which statement describes the graph of this polynomial function?
f(x)=x^5 - 6x^4 + 9x^3
a. The graph crosses the x axis at x = 0 and touches the x axis at x = 3.
b. The graph touches the x axis at x = 0 and crosses the x axis at x = 3.
c. The graph crosses the x axis at x = 0 and touches the x axis at x = –3.
d. The graph touches the x axis at x = 0 and crosses the x axis at x = –3.