Which of the following describes a failed QC sample?

A failed QC sample is characterized as one that is non-comparable with VT, which stands for Verification Testing. This means that the sample does not align with the expected values or standards established during verification processes. In Quality Control, the ability to compare the test results of a sample against a benchmark or standard is crucial. If a sample fails to demonstrate comparability, it indicates that the material or process being tested does not conform to the required specifications, which is a key indicator of failure in QC terms.

The other options describe scenarios where the QC samples meet certain criteria or standards. A sample that meets the standards or is compliant with the guidelines would typically be considered successful. Submitting a sample with an EAR (Expedited Action Report) does not inherently imply failure; the context and outcomes of that report determine its status. Thus, the defining characteristic of a failed QC sample is its lack of comparability with the established verification testing parameters.