How does "mutation testing" help evaluate the quality of a test suite beyond code coverage, and what is its main practical drawback?

A It reveals whether tests can actually detect introduced faults (mutants), but running many mutants against a full test suite can be computationally expensive B It has no drawbacks and should always be run on every commit C It only works on compiled languages and never on interpreted ones D It replaces the need for code coverage tools entirely with no added cost