The use of a control sample is primarily to verify what aspect of lab results?

The use of a control sample is primarily to verify the accuracy and reliability of test results. Control samples are essential in laboratory testing as they provide a known reference point. By comparing the results of the test samples against the control, laboratory personnel can determine whether the test is functioning correctly and yielding valid results. If the control sample produces expected results, it serves as confirmation that the testing procedure is reliable and that the instruments and reagents used are performing as intended.

This process is crucial for quality assurance in laboratory work, ensuring that diagnostic tests yield accurate information that can be relied upon for patient care. Therefore, the primary purpose of including control samples in testing protocols is to uphold the integrity of the lab's findings and to ensure consistent performance over time. The other choices do not directly relate to the verification of test results in the same way as control samples do.