PLEASE HELP ASAP I'LL GIVE BRAINLIEST 100 POINTS!! The graph below shows how the temperature of a substance varies with time during a certain science experiment. (attached)

Assume that there are no other x-intercepts besides those showing on the graph. Which equation best models the function f(x) , the Celsius temperature of the substance after x minutes, shown in the graph?

A
f(x)=1/9(x−1)^2 (x−3)(x−6)

B
f(x)=2(x−1)^2 (x−3)(x−6)

C
f(x)=1/9(x+1)(x+3)(x+6)

D
f(x)=2(x+1)(x+3)(x+6)