A patient receives a 125-mg injection of medicine every 6 hours. The table shows the amount of medicine in the bloodstream, m(t), after t hours. For which hour is the rate of change of medicine in the bloodstream expected to be the largest, based on the data?
t, hours 0 6 12 18 24
m(t), milligrams 125 188 219 235 243
Group of answer choices
1 hour
8 hours
15 hours
19 hours