The number of students, y, still participating in the final round of a school spelling bee compared to the number of spelling words attempted, x, can be represented by a scatter plot with a negative, linear association. Which equation for a line of best fit could be used to represent the number of students still participating in the final round of the school spelling bee given a number of spelling words attempted? A: y=0.5 + 10
B: y= -0.5x^2 + 10
C: y= 0.5x^2 + 10
D: y= -0.5x +10