The regression equation y=4x+20 approximates the number of people attending a picnic, y, given the number of flyers used to advertise it, x. Which statement is true? A-for every person attending a picnic, the number of flyers used to advertise it increases by 20.
B-for every person attending a picnic, the number of flyers used to advertise it increases by 4.
C-for every extra flyer used in advertising, the attendance increases by 4 people
D-for every extra flyer used in advertising, the attendance increases by 20 people