Select the correct answer.
 To bake one cake, Drew uses 18 ounces of flour. He has 850 ounces of flour. Let y represent the ounces of flour left and x represent the number of cakes he has baked. When the situation is modeled on a graph, what are the slope and the y-intercept of the line representing this situation?
 A. 
 slope = 850 and y-intercept = 18
 B. 
 slope = 18 and y-intercept = 850
 C. 
 slope = -18 and y-intercept = 850
 D. 
 slope = 850 and y-intercept = -18