The function r(t) is the rate that knee replacement surgeries are performed in the United States in thousands of surgeries per month and t is the number of months since the beginning of 2014. There were about 719,000 knee replacement surgeries in 2014. Choose the correct expression. O for(t) dt = 719 1000 for(t) dt = 719 for(t) dt = 719, 000 719 for(t) dt = 0 ( 719 + So r(t) dt = 1