How often must each resident's drug regimen be reviewed by a licensed pharmacist?

The correct choice, which indicates that each resident's drug regimen must be reviewed by a licensed pharmacist monthly, aligns with the regulatory requirements for long-term care facilities. Monthly reviews are mandated to ensure the safe and effective use of medications for residents, allowing for timely identification of potential drug interactions, side effects, or ineffective therapies. This frequency enables healthcare teams to make necessary adjustments to residents' medication plans based on changing health conditions or response to treatments.

While other review periods could be beneficial, monthly reviews are specifically designed to maintain a high standard of care by providing regular oversight of pharmacotherapy. This approach helps to safeguard against adverse drug events and promotes optimal therapeutic outcomes for residents in long-term care settings. Ensuring that a licensed pharmacist conducts these reviews regularly is crucial for enhancing patient safety and improving the overall quality of care in health facilities.