A student conducts an experiment with a spring. They apply different forces to the spring and measure the change in length. The student then draws a graph of the applied force versus the change in length. If the slope of the graph is 32.58 N/m and the manufacturer of the spring states that the spring coefficient is 30 N/m, what is the percent error in this experiment?
A) 8.2%
B) 8.6%
C) 2%
D) 12.5%
E) 6.4%