Which of the Following Is Characteristic of Control Samples

Multiple Choice

Which of the following is characteristic of control samples?

A) They are used once after every five patient samples are processed.
B) They serve as a check on the accuracy of the test.
C) The results from a patient sample and control sample should have different results.
D) They have unknown results when the test is performed.
E) They are used only after equipment has been serviced or replaced.