The end-of-day values of a stock market index for the week of December 9- 13, are graphed to the right, where x is the day of the month. On what day did the index show the greatest rate of increase? On what day did it show the greatest rate of decrease? Give the rates. 16030- (9,16006) 15970- (10.15948) 15910- Stock Market Index 15850 (11.15861) (13, 15808) 15790- (12. 15/79) 15730- 8 9 10 11 12 13 14 Day of the Month On what day did the index show the greatest rate of increase? O A. December 13 O B. December 11 O C. December 10 O D. December 12 What was the greatest rate of increase? The rate was |points/day. (Simplify your answer.) On what day did the index show the greatest rate of decrease? O A. December 13 O B. December 12 O C. December 10