The graph above plots the measurements of the radioactive decay of an element, along with a line of best fit. Why do some of the data points not lie on the line of best fit, but appear above and below it?
[Figure: Graph titled "Radioactive Decay" showing count vs time/seconds, with exponential decay curve from 600 to near 0 over 400 seconds, with scattered data points around the fitted line]
A. Not all of the α or β or γ radiations are measured
B. The source decays in a random manner
C. The background count is not zero
D. Inaccurate measurements by the experimenter