The accepted value for the density of iron is 7.9 g/ml. Which of the following sets of experimental data for the density of iron is the most accurate? 
a) 7.6 g/ml, 7.8 g/ml, 8.0 g/ml 
b) 7.7 g/ml, 7.9 g/ml, 8.1 g/ml 
c) 7.5 g/ml, 8.0 g/ml, 8.2 g/ml 
d) 7.8 g/ml, 7.9 g/ml, 8.2 g/ml