What must be a factor of the polynomial function f(x) graphed on the coordinate plane below?

On a coordinate plane, a parabola opens up. It goes through (0, 3), has a vertex at (3.5, 3), and goes through (6, 0).
x – 3
x – 1
x + 1
x + 3

Suppose that 3% of all athletes are using the endurance-enhancing hormone epo (you should be able to simply compute the percentage of all athletes that are not using epo). for our purposes, a “positive” test result is one that indicates presence of epo in an athlete’s bloodstream. the probability of a positive result, given the presence of epo is .99. the probability of a negative result, when epo is not present, is .90. what is the probability that a randomly selected athlete tests positive for epo? 0.0297