Which of the following best defines the term 'therapeutic window' in clinical pharmacology?

• A. The difference between a drug's half‑life and dosing interval which determines accumulation and steady state prior to therapeutic monitoring.
• B. A single numerical ratio calculated by dividing the highest tolerated dose in animals by the lowest observed effective dose in humans, used solely for regulatory purposes rather than guiding dosing in individual patients.
• C. The range of actual dosages between the minimum effective dose and the minimum toxic dose in which a drug is both effective and not harmful to the patient.
• D. The measured concentration of drug in plasma required to inhibit 50% of target organisms in vitro under standardized laboratory conditions without any relation to patient toxicity.

Answer: (C)