D. i.e. (Quantal dose - response curve) (34- Lippincots's 4th)Only a quantal dose - response curve gives information about differences in the sensitivity of individuals to increasing doses of a drug* ED50 is a measure of potency**EFFICACY (Intrinsic activity) - determined from graded dose response plotsEfficacy is more important than drug potency. A drug with greater efficacy is more therapeutically beneficial than one that more potent**THERAPEUTIC INDEX (TD50/ED50) is a measure of a drugs safety**. Because a larger value indicates a wide margin between doses that are effective an doses that are toxic