Final answer:
True, entities handling controlled substances must keep an inventory record for five years to comply with DEA regulations and prevent illegal distribution.
Step-by-step explanation:
The statement that an inventory record of each controlled substance transaction at an office must be kept for five years is true. Under the regulations enforced by the Drug Enforcement Administration (DEA), healthcare providers, pharmacies, and other entities that handle controlled substances are required to maintain accurate records and inventories of all transactions involving controlled substances. These records are crucial for compliance with the Controlled Substances Act and to prevent the illegal distribution of prescription drugs. The standard duration for retaining these records is five years, although some states might have stricter requirements. It's important for any entity managing controlled substances to stay informed on both federal and state regulations regarding record retention.