L-J cha is used for monitoring aEUR'

Precision & Accuracy A Levey-Jenings cha is a graph that quality control data is plotted on to give a visual indication whether a laboratory test is working well Daily Documentation and evaluation of quality control is vital to diligently monitor sources of error. One of the most commonly used methods for documentation is the Levey-Jennings control cha (often referred to as the L-J cha). The Levey-Jennings cha usually has the days of the month plotted on the X-axis and the control observations plotted on the Y-axis. The L-J cha is plotted each day. Monitoring over time provides information about the precision and long term accuracy of measurement. I'm not sure what the ans could be, but after reading available material on net, if I was to select one option, 1 would go for option 'b' i.e. Precision.