At a certain​ school, the number of student tickets sold for a home football game can be modeled by ​S(p)=61p​+8400, where p is the winning percent of the home team. The number of nonstudent tickets sold for these home games is given by ​N(p)=0.2p^2+18p+4300

Which statement is true about the extreme value of the given quadratic equation? a. the equation has a maximum value with a y-coordinate of -21. b. the equation has a maximum value with a y-coordinate of -27. c. the equation has a minimum value with a y-coordinate of -21. d. the equation has a minimum value with a y-coordinate of -27.