When Inspecting an Internal Quality-Control Plot for a Blood Gas

Multiple Choice

When inspecting an internal quality-control plot for a blood gas analyzer, you notice several data points sporadically appearing outside the 2 standard deviation (SD) range. This represents what type of analytic error?
1) Random error
2) Bias
3) Imprecision
4) Systematic error

A) 1 and 3 only
B) 2 and 4 only
C) 1, 2, and 4 only
D) 1, 2, 3, and 4