The correct answer is D. Therapeutic index
Step-by-step explanation:
In medicine, the therapeutic index is the range that defines the measure of a medicine that is safe or recommended as treatment and the measure that is toxic or has negative effects. This index is essential for the prescriptions of medicines because it acts as a guide to provide efficient treatments and toxicity. For example, the therapeutic index of paracetamol (painkiller) is between 10mg per kilo to around 150mg per kilo, which means taking doses above 150mg per kilo causes toxicity. According to this, the correct answer is the Therapeutic Index.