Final answer:
To maximize revenue from selling vitamins, the turning point of the function R(x) = 500x - 0.001x^2 is calculated using the vertex formula -b/(2a), resulting in the sale of 250,000 bottles.
Step-by-step explanation:
To determine how many bottles of vitamins should be sold to maximize revenue, one must find the vertex of the parabolic revenue function given by R(x) = 500x - 0.001x^2. The vertex can be found by using the formula -b/(2a) where a and b are the coefficients of x^2 and x in the quadratic function respectively. For the function R(x), a is -0.001 and b is 500.
Plugging into the vertex formula gives us x = -500 / (2 * -0.001) = 250,000. Therefore, to maximize revenue, 250,000 bottles of vitamins must be sold, which corresponds to answer choice A.