t 1 5 8 13 R (t) 1 10 17 32 The differentiable function R is increasing, and the graph of R is concave down. Values of R (t) at selected values of t are given in the table above. The trapezoidal sum (5 - 1) 2 ) + (8 - 5 ) ( 17+10 2 + (13 - 8) 17+32 2 approximates R (t) dt. Which of the following statements is true? A The trapezoidal sum is an underestimate for R (t) d't because R is increasing. 13 B The trapezoidal sum is an overestimate for R (t) dt because R is increasing. 13 C The trapezoidal sum is an underestimate for / R (t) dt because the graph of R is concave down. D The trapezoidal sum is an overestimate for R (t) d't because the graph of R is concave down