Final answer:
The practice must update their CLIA certificate within 30 days if they are moving to a new location, as changes in physical location require immediate certificate updates. Therefore, the correct option is c).
Step-by-step explanation:
According to CLIA (Clinical Laboratory Improvement Amendments) regulations, any time there is a change in ownership, directorship, location, or type of testing performed, the facility must update its CLIA certificate information. Although Dr. Miller is retiring in scenario A, if Dr. Hansen is still listed as the owner/medical director, the CLIA certificate does not necessarily need immediate updating. Renewing the CLIA certificate in scenario B is part of regular maintenance and is not typically a change that requires an update within 30 days. Adding a new test in scenario D, not covered under the practice's current CLIA certificate, would indeed necessitate an application for a certificate that includes the new test, but it does not require updating existing information within 30 days.